diff --git a/collects/macro-debugger/syntax-browser/display.rkt b/collects/macro-debugger/syntax-browser/display.rkt
index 9a242f7..e44436d 100644
--- a/collects/macro-debugger/syntax-browser/display.rkt
+++ b/collects/macro-debugger/syntax-browser/display.rkt
@@ -2,7 +2,7 @@
 (require racket/class
          racket/gui/base
          racket/list
-         racket/block
+         racket/pretty
          framework
          unstable/class-iop
          "pretty-printer.rkt"
@@ -12,46 +12,52 @@
 (provide print-syntax-to-editor
          code-style)
 
-(define TIME-PRINTING? #f)
+(define-syntax-rule (uninterruptible e ...)
+  ;; (coarsely) prevent breaks within editor operations
+  (parameterize-break #f (begin e ...))
+  #|
+  (parameterize-break #f
+    (let ([ta (now)])
+      (begin0 (begin e ...)
+        (let ([tb (now)])
+          (eprintf "****\n")
+          (pretty-write '(begin e ...) (current-error-port))
+          (eprintf "  -- ~s ms\n\n" (- tb ta))))))
+  |#)
 
-(define-syntax-rule (now)
-  (if TIME-PRINTING?
-      (current-inexact-milliseconds)
-      0))
+(define (now) (current-inexact-milliseconds))
 
 ;; FIXME: assumes text never moves
 
 ;; print-syntax-to-editor : syntax text controller<%> config number number
 ;;                       -> display<%>
+;; Note: must call display<%>::refresh to finish styling.
 (define (print-syntax-to-editor stx text controller config columns
                                 [insertion-point (send text last-position)])
-  (block
-   (define output-port (open-output-string/count-lines))
-   (define range
-     (pretty-print-syntax stx output-port 
-                          (send/i controller controller<%> get-primary-partition)
-                          (length (send/i config config<%> get-colors))
-                          (send/i config config<%> get-suffix-option)
-                          (send config get-pretty-styles)
-                          columns))
-   (define output-string (get-output-string output-port))
-   (define output-length (sub1 (string-length output-string))) ;; skip final newline
-   (fixup-parentheses output-string range)
-   (send text begin-edit-sequence #f)
-   (send text insert output-length output-string insertion-point)
-   (define display
-     (new display%
-          (text text)
-          (controller controller)
-          (config config)
-          (range range)
-          (start-position insertion-point)
-          (end-position (+ insertion-point output-length))))
-   (send display initialize)
-   (send text end-edit-sequence)
-   display))
+  (define output-port (open-output-string/count-lines))
+  (define range
+    (pretty-print-syntax stx output-port 
+                         (send/i controller controller<%> get-primary-partition)
+                         (length (send/i config config<%> get-colors))
+                         (send/i config config<%> get-suffix-option)
+                         (send config get-pretty-styles)
+                         columns))
+  (define output-string (get-output-string output-port))
+  (define output-length (sub1 (string-length output-string))) ;; skip final newline
+  (fixup-parentheses output-string range)
+  (with-unlock text
+    (uninterruptible
+     (send text insert output-length output-string insertion-point))
+    (new display%
+         (text text)
+         (controller controller)
+         (config config)
+         (range range)
+         (start-position insertion-point)
+         (end-position (+ insertion-point output-length)))))
 
 ;; display%
+;; Note: must call refresh method to finish styling.
 (define display%
   (class* object% (display<%>)
     (init-field/i [controller controller<%>]
@@ -66,12 +72,15 @@
 
     (define extra-styles (make-hasheq))
 
+    (define auto-refresh? #f) ;; FIXME: delete or make init arg
+
     ;; initialize : -> void
-    (define/public (initialize)
-      (send text change-style base-style start-position end-position #f)
-      (apply-primary-partition-styles)
-      (add-clickbacks)
-      (refresh))
+    (define/private (initialize)
+      (uninterruptible
+       (send text change-style base-style start-position end-position #f))
+      (uninterruptible (apply-primary-partition-styles))
+      (uninterruptible (add-clickbacks))
+      (when auto-refresh? (refresh)))
 
     ;; add-clickbacks : -> void
     (define/private (add-clickbacks)
@@ -103,18 +112,15 @@
     ;; refresh : -> void
     ;; Clears all highlighting and reapplies all non-foreground styles.
     (define/public (refresh)
-      (with-unlock text
-        (send* text 
-          (begin-edit-sequence #f)
-          (change-style (unhighlight-d) start-position end-position))
-        (apply-extra-styles)
-        (let ([selected-syntax
-               (send/i controller selection-manager<%>
-                      get-selected-syntax)])
-          (apply-secondary-relation-styles selected-syntax)
-          (apply-selection-styles selected-syntax))
-        (send* text
-          (end-edit-sequence))))
+      (uninterruptible
+       (with-unlock text
+         (send text change-style (unhighlight-d) start-position end-position)
+         (apply-extra-styles)
+         (let ([selected-syntax
+                (send/i controller selection-manager<%>
+                        get-selected-syntax)])
+           (apply-secondary-relation-styles selected-syntax)
+           (apply-selection-styles selected-syntax)))))
 
     ;; get-range : -> range<%>
     (define/public (get-range) range)
@@ -130,13 +136,13 @@
       (let ([style-delta (highlight-style-delta hi-color #f)])
         (for ([stx stxs])
           (add-extra-styles stx (list style-delta))))
-      (refresh))
+      (when auto-refresh? (refresh)))
 
     ;; underline-syntaxes : (listof syntax) -> void
     (define/public (underline-syntaxes stxs)
       (for ([stx stxs])
         (add-extra-styles stx (list underline-style-delta)))
-      (refresh))
+      (when auto-refresh? (refresh)))
 
     ;; add-extra-styles : syntax (listof style) -> void
     (define/public (add-extra-styles stx styles)
@@ -236,7 +242,8 @@
 
     ;; Initialize
     (super-new)
-    (send/i controller controller<%> add-syntax-display this)))
+    (send/i controller controller<%> add-syntax-display this)
+    (initialize)))
 
 ;; fixup-parentheses : string range -> void
 (define (fixup-parentheses string range)
diff --git a/collects/macro-debugger/syntax-browser/properties.rkt b/collects/macro-debugger/syntax-browser/properties.rkt
index 3773a2c..2bf64f1 100644
--- a/collects/macro-debugger/syntax-browser/properties.rkt
+++ b/collects/macro-debugger/syntax-browser/properties.rkt
@@ -4,6 +4,7 @@
          framework
          unstable/class-iop
          "interfaces.rkt"
+         "util.rkt"
          "../util/mpi.rkt"
          "../util/stxobj.rkt")
 (provide properties-view%
@@ -58,17 +59,12 @@
 
     ;; refresh : -> void
     (define/public (refresh)
-      (send* text
-        (lock #f)
-        (begin-edit-sequence #f)
-        (erase))
-      (if (syntax? selected-syntax)
-          (refresh/mode mode)
-          (refresh/mode #f))
-      (send* text
-        (end-edit-sequence)
-        (lock #t)
-        (scroll-to-position 0)))
+      (with-unlock text
+        (send text erase)
+        (if (syntax? selected-syntax)
+            (refresh/mode mode)
+            (refresh/mode #f)))
+      (send text scroll-to-position 0))
 
     ;; refresh/mode : symbol -> void
     (define/public (refresh/mode mode)
diff --git a/collects/macro-debugger/syntax-browser/snip-decorated.rkt b/collects/macro-debugger/syntax-browser/snip-decorated.rkt
index 87f2db1..442a09a 100644
--- a/collects/macro-debugger/syntax-browser/snip-decorated.rkt
+++ b/collects/macro-debugger/syntax-browser/snip-decorated.rkt
@@ -7,6 +7,7 @@
          "controller.rkt"
          "properties.rkt"
          "prefs.rkt"
+         "util.rkt"
          (except-in "snip.rkt"
                     snip-class))
 
@@ -47,26 +48,21 @@
     (define open? #f)
 
     (define/public (refresh-contents)
-      (send* -outer
-        (begin-edit-sequence)
-        (lock #f)
-        (erase))
-      (do-style (if open? open-style closed-style))
-      (outer:insert (if open? (hide-icon) (show-icon))
-                    style:hyper
-                    (if open?
-                        (lambda _
-                          (set! open? #f)
-                          (refresh-contents))
-                        (lambda _
-                          (set! open? #t)
-                          (refresh-contents))))
-      (for-each (lambda (s) (outer:insert s))
-                (if open? (open-contents) (closed-contents)))
-      (send* -outer
-        (change-style top-aligned 0 (send -outer last-position))
-        (lock #t)
-        (end-edit-sequence)))
+      (with-unlock -outer
+        (send -outer erase)
+        (do-style (if open? open-style closed-style))
+        (outer:insert (if open? (hide-icon) (show-icon))
+                      style:hyper
+                      (if open?
+                          (lambda _
+                            (set! open? #f)
+                            (refresh-contents))
+                          (lambda _
+                            (set! open? #t)
+                            (refresh-contents))))
+        (for-each (lambda (s) (outer:insert s))
+                  (if open? (open-contents) (closed-contents)))
+        (send -outer change-style top-aligned 0 (send -outer last-position))))
 
     (define/private (do-style style)
       (show-border (memq 'border style))
diff --git a/collects/macro-debugger/syntax-browser/snip.rkt b/collects/macro-debugger/syntax-browser/snip.rkt
index 1b6a8f1..82a1f28 100644
--- a/collects/macro-debugger/syntax-browser/snip.rkt
+++ b/collects/macro-debugger/syntax-browser/snip.rkt
@@ -7,6 +7,7 @@
          "display.rkt"
          "controller.rkt"
          "keymap.rkt"
+         "util.rkt"
          "prefs.rkt")
 
 (provide syntax-snip%
@@ -34,12 +35,10 @@
     ;;(set-margin 2 2 2 2)
     (set-inset 0 0 0 0)
 
-    (send text begin-edit-sequence)
-    (send text change-style (make-object style-delta% 'change-alignment 'top))
     (define display
-      (print-syntax-to-editor stx text controller config columns))
-    (send text lock #t)
-    (send text end-edit-sequence)
+      (with-unlock text
+        (send text change-style (make-object style-delta% 'change-alignment 'top))
+        (print-syntax-to-editor stx text controller config columns)))
     (send text hide-caret #t)
 
     (setup-keymap text)
diff --git a/collects/macro-debugger/syntax-browser/util.rkt b/collects/macro-debugger/syntax-browser/util.rkt
index 1c3ad52..2efd494 100644
--- a/collects/macro-debugger/syntax-browser/util.rkt
+++ b/collects/macro-debugger/syntax-browser/util.rkt
@@ -10,13 +10,16 @@
     [(with-unlock text . body)
      (let* ([t text]
             [locked? (send t is-locked?)])
-       (send* t
-         (lock #f)
-         (begin-edit-sequence #f))
-       (begin0 (let () . body)
-         (send* t
-           (end-edit-sequence)
-           (lock locked?))))]))
+       (dynamic-wind
+         (lambda ()
+           (send* t
+             (begin-edit-sequence #f)
+             (lock #f)))
+         (lambda () . body)
+         (lambda ()
+           (send* t
+             (lock locked?)
+             (end-edit-sequence)))))]))
 
 ;; make-text-port : text (-> number) -> port
 ;; builds a port from a text object.  
diff --git a/collects/macro-debugger/syntax-browser/widget.rkt b/collects/macro-debugger/syntax-browser/widget.rkt
index f8292fe..8b36dc7 100644
--- a/collects/macro-debugger/syntax-browser/widget.rkt
+++ b/collects/macro-debugger/syntax-browser/widget.rkt
@@ -112,21 +112,25 @@
                                #:hi-colors [hi-colors null]
                                #:hi-stxss [hi-stxss null]
                                #:substitutions [substitutions null])
-      (let ([display (internal-add-syntax stx)]
-            [definite-table (make-hasheq)])
+      (with-unlock -text
+        (define display
+          (print-syntax-to-editor stx -text controller config
+                                  (calculate-columns)
+                                  (send -text last-position)))
+        (define definite-table (make-hasheq))
+        (send -text insert "\n")
         (let ([range (send/i display display<%> get-range)]
               [offset (send/i display display<%> get-start-position)])
           (for ([subst substitutions])
             (for ([r (send/i range range<%> get-ranges (car subst))])
-              (with-unlock -text
-                (send -text insert (cdr subst)
-                      (+ offset (car r))
-                      (+ offset (cdr r))
-                      #f)
-                (send -text change-style
-                      (code-style -text (send/i config config<%> get-syntax-font-size))
-                      (+ offset (car r))
-                      (+ offset (cdr r)))))))
+              (send -text insert (cdr subst)
+                    (+ offset (car r))
+                    (+ offset (cdr r))
+                    #f)
+              (send -text change-style
+                    (code-style -text (send/i config config<%> get-syntax-font-size))
+                    (+ offset (car r))
+                    (+ offset (cdr r))))))
         (for ([hi-stxs hi-stxss] [hi-color hi-colors])
           (send/i display display<%> highlight-syntaxes hi-stxs hi-color))
         (for ([definite definites])
@@ -151,6 +155,7 @@
           (send/i display display<%> underline-syntaxes
                  (append (apply append (map get-shifted binders))
                          binders))
+          (send display refresh)
           ;; Make arrows (& billboards, when enabled)
           (for ([id (send/i range range<%> get-identifier-list)])
             (define definite? (hash-ref definite-table id #f))
@@ -203,19 +208,6 @@
 
     (define/public (get-text) -text)
 
-    ;; internal-add-syntax : syntax -> display
-    (define/private (internal-add-syntax stx)
-      (with-unlock -text
-        (let ([display
-               (print-syntax-to-editor stx -text controller config
-                                       (calculate-columns)
-                                       (send -text last-position))])
-          (send* -text
-            (insert "\n")
-            ;;(scroll-to-position current-position)
-            )
-          display)))
-
     (define/private (calculate-columns)
       (define style (code-style -text (send/i config config<%> get-syntax-font-size)))
       (define char-width (send style get-text-width (send -ecanvas get-dc)))
diff --git a/collects/macro-debugger/view/gui-util.rkt b/collects/macro-debugger/view/gui-util.rkt
index b08fe84..0518a36 100644
--- a/collects/macro-debugger/view/gui-util.rkt
+++ b/collects/macro-debugger/view/gui-util.rkt
@@ -3,13 +3,13 @@
          racket/gui/base)
 (provide status-area%)
 
-(define SHOW-DELAY 1000)
-(define FADE-DELAY 400)
-(define NAP-TIME 0.1)
+(define FADE-DELAY 1000)
+(define NAP-TIME 0.01)
 
 (define status-area%
   (class* object% (#| status-area<%> |#)
-    (init parent)
+    (init parent
+          stop-callback)
 
     (define lock (make-semaphore 1))
 
@@ -18,7 +18,7 @@
                     (lambda () . body)
                     (lambda () (semaphore-post lock))))
 
-    (define timer (new timer% (notify-callback (lambda () (update)))))
+    (define timer (new timer% (notify-callback (lambda () (fade-out)))))
 
     (define pane
       (new horizontal-pane%
@@ -29,69 +29,78 @@
            (parent pane)
            (label "")
            (auto-resize #t)
+           (stretchable-width #t)
+           (style '(deleted))))
+    (define stop-button
+      (new button%
+           (parent pane)
+           (label "Stop")
+           (enabled #f)
+           (callback stop-callback)
            (style '(deleted))))
 
+    (define visible? #t)
+
+    (define/public (set-visible new-visible?)
+      (with-lock
+       (set! visible? new-visible?)
+       (show (memq state '(shown fade)))))
+
     #|
-    Four states:
-      - 'none    = no message displayed, none pending
-      - 'pending = no message displayed, message pending
+    Three states:
+      - 'none    = no message displayed
       - 'shown   = message displayed
       - 'fade    = message displayed, waiting to erase
+
+    Timer is only started during 'fade state.
     |#
     (define state 'none)
-    (define pending #f)
 
-    (define/public (set-status msg [immediate? #f])
+    (define/private (show ?)
+      (send pane change-children
+            (lambda _
+              (if (and ? visible?)
+                  (list message stop-button)
+                  null))))
+
+    (define/public (set-status msg)
       (with-lock
-       (when immediate? (send timer stop))
        (cond [msg
               (case state
                 ((none)
-                 (cond [#f ;; immediate?
-                        (set! state 'shown)
-                        (send pane change-children (lambda _ (list message)))
-                        (send message set-label msg)
-                        (set! pending #f)
-                        (sleep/yield NAP-TIME)]
-                       [else
-                        (set! state 'pending)
-                        (set! pending msg)
-                        (unless immediate? (send timer start SHOW-DELAY #t))]))
-                ((pending)
-                 (set! pending msg))
+                 (send message set-label msg)
+                 (send message enable #t)
+                 (show #t)
+                 (sleep/yield NAP-TIME)
+                 (set! state 'shown))
                 ((shown)
                  (send message set-label msg))
                 ((fade)
                  (send timer stop) ;; but (update) may already be waiting
-                 (set! state 'shown)
-                 (send message set-label msg)))]
+                 (send message set-label msg)
+                 (send message enable #t)
+                 (set! state 'shown)))]
              [(not msg)
               (case state
-                ((none) (void))
-                ((pending)
-                 (send timer stop) ;; but (update) may already be waiting
-                 (set! state 'none)
-                 (set! pending #f))
                 ((shown)
-                 (set! state 'fade)
-                 (unless immediate? (send timer start FADE-DELAY #t))))])
-       (when immediate? (update*) (sleep/yield NAP-TIME))))
+                 (send timer start FADE-DELAY #t)
+                 (send message enable #f)
+                 (set! state 'fade)))])))
 
-    (define/private (update)
-      (with-lock (update*)))
+    (define/private (fade-out)
+      (with-lock (fade-out*)))
 
-    (define/private (update*)
+    (define/private (fade-out*)
       (case state
-        ((pending)
-         (set! state 'shown)
-         (send pane change-children (lambda _ (list message)))
-         (send message set-label pending)
-         (set! pending #f))
         ((fade)
-         (set! state 'none)
-         (send pane change-children (lambda _ null)))
-        ((none shown)
+         (show #f)
+         (send message set-label "")
+         (set! state 'none))
+        (else
          ;; timer not stopped in time; do nothing
          (void))))
 
+    (define/public (enable-stop ?)
+      (send stop-button enable ?))
+
     (super-new)))
diff --git a/collects/macro-debugger/view/step-display.rkt b/collects/macro-debugger/view/step-display.rkt
index 471632f..28544f0 100644
--- a/collects/macro-debugger/view/step-display.rkt
+++ b/collects/macro-debugger/view/step-display.rkt
@@ -31,9 +31,13 @@
 
     (define/public (add-internal-error part exn stx events)
       (send/i sbview sb:syntax-browser<%> add-text
-              (if part
-                  (format "Macro stepper error (~a)" part)
-                  "Macro stepper error"))
+              (string-append
+               (if (exn:break? exn)
+                   "Macro stepper was interrupted"
+                   "Macro stepper error")
+               (if part
+                   (format " (~a)" part)
+                   "")))
       (when (exn? exn)
         (send/i sbview sb:syntax-browser<%> add-text " ")
         (send/i sbview sb:syntax-browser<%> add-clickback "[details]"
@@ -44,7 +48,9 @@
       (when stx (send/i sbview sb:syntax-browser<%> add-syntax stx)))
 
     (define/private (show-internal-error-details exn events)
-      (case (message-box/custom "Macro stepper internal error"
+      (case (message-box/custom (if (exn:break? exn)
+                                    "Macro stepper was interrupted"
+                                    "Macro stepper internal error")
                                 (format "Internal error:\n~a" (exn-message exn))
                                 "Show error"
                                 "Dump debugging file"
diff --git a/collects/macro-debugger/view/stepper.rkt b/collects/macro-debugger/view/stepper.rkt
index 731a6e7..b028065 100644
--- a/collects/macro-debugger/view/stepper.rkt
+++ b/collects/macro-debugger/view/stepper.rkt
@@ -4,6 +4,7 @@
          racket/list
          racket/match
          racket/gui/base
+         racket/pretty
          unstable/class-iop
          "interfaces.rkt"
          "extensions.rkt"
@@ -15,6 +16,7 @@
          "../model/deriv-util.rkt"
          "cursor.rkt"
          "gui-util.rkt"
+         "../syntax-browser/util.rkt"
          unstable/gui/notify
          (only-in mzscheme [#%top-interaction mz-top-interaction]))
 (provide macro-stepper-widget%
@@ -108,7 +110,10 @@
       (update/preserve-view))
 
     (define superarea (new vertical-pane% (parent parent)))
-    (define area (new vertical-panel% (parent superarea)))
+    (define area
+      (new vertical-panel%
+           (parent superarea)
+           (enabled #f)))
     (define supernavigator
       (new horizontal-panel%
            (parent area)
@@ -148,7 +153,9 @@
            (config config)))
 
     (define status-area
-      (new status-area% (parent superarea)))
+      (new status-area%
+           (parent superarea)
+           (stop-callback (lambda _ (stop-processing)))))
 
     (send/i sbc sb:controller<%>
            listen-selected-syntax
@@ -252,8 +259,8 @@
                   (list navigator extra-navigator)
                   (list navigator)))))
 
-    (define/public (change-status msg [immediate? #f])
-      (send status-area set-status msg immediate?))
+    (define/public (change-status msg)
+      (send status-area set-status msg))
 
     ;; Navigation
     (define/public-final (navigate-to-start)
@@ -295,15 +302,57 @@
       (send nav:end enable (and ? term (send/i term term-record<%> has-next?)))
       (send nav:text enable (and ? term #t))
       (send nav:up enable (and ? (cursor:has-prev? terms)))
-      (send nav:down enable (and ? (cursor:has-next? terms))))
+      (send nav:down enable (and ? (cursor:has-next? terms)))
+      (send status-area enable-stop (not ?)))
 
     ;; Async update & refresh
 
+    (define update-thread #f)
+
+    (define ASYNC-DELAY 500) ;; milliseconds
+
+    (define/private (call-with-update-thread thunk)
+      (send status-area set-visible #f)
+      (let* ([lock (make-semaphore 1)] ;; mutex for status variable
+             [status #f] ;; mutable: one of #f, 'done, 'async
+             [thd
+              (parameterize-break #f
+                (thread (lambda ()
+                          (with-handlers ([exn:break?
+                                           (lambda (e)
+                                             (change-status "Interrupted")
+                                             (void))])
+                            (parameterize-break #t
+                              (thunk)
+                              (change-status #f)))
+                          (semaphore-wait lock)
+                          (case status
+                            ((async)
+                             (set! update-thread #f)
+                             (with-eventspace
+                              (enable/disable-buttons #t)))
+                            (else
+                             (set! status 'done)))
+                          (semaphore-post lock))))])
+        (sync thd (alarm-evt (+ (current-inexact-milliseconds) ASYNC-DELAY)))
+        (semaphore-wait lock)
+        (case status
+          ((done)
+           ;; Thread finished; enable/disable skipped, so do it now to update.
+           (enable/disable-buttons #t))
+          (else
+           (set! update-thread thd)
+           (send status-area set-visible #t)
+           (enable/disable-buttons #f)
+           (set! status 'async)))
+        (semaphore-post lock)))
+
     (define-syntax-rule (with-update-thread . body)
-      (begin (enable/disable-buttons #f)
-             (thread (lambda ()
-                       (let () . body)
-                       (enable/disable-buttons #t)))))
+      (call-with-update-thread (lambda () . body)))
+
+    (define/private (stop-processing)
+      (let ([t update-thread])
+        (when t (break-thread t))))
 
     ;; Update
 
@@ -362,30 +411,23 @@
       (define text (send/i sbview sb:syntax-browser<%> get-text))
       (define position-of-interest 0)
       (define multiple-terms? (> (length (cursor->list terms)) 1))
-      (send text begin-edit-sequence #f)
-      (send/i sbview sb:syntax-browser<%> erase-all)
 
-      ;;(change-status "Showing prefix")
-      ;;(sleep 1)
-      (update:show-prefix)
-      (when multiple-terms? (send/i sbview sb:syntax-browser<%> add-separator))
-      (set! position-of-interest (send text last-position))
-      ;;(change-status "Showing current step")
-      ;;(sleep 1)
-      (update:show-current-step)
-      (when multiple-terms? (send/i sbview sb:syntax-browser<%> add-separator))
-      ;;(change-status "Showing suffix")
-      ;;(sleep 1)
-      (update:show-suffix)
-      (send text end-edit-sequence)
+      (with-unlock text
+        (send/i sbview sb:syntax-browser<%> erase-all)
+        (update:show-prefix)
+        (when multiple-terms? (send/i sbview sb:syntax-browser<%> add-separator))
+        (set! position-of-interest (send text last-position))
+        (update:show-current-step)
+        (when multiple-terms? (send/i sbview sb:syntax-browser<%> add-separator))
+        (update:show-suffix))
+
       (send text scroll-to-position
             position-of-interest
             #f
             (send text last-position)
             'start)
       (update-nav-index)
-      (change-status #f)
-      #| (enable/disable-buttons) |#)
+      (change-status #f))
 
     ;; --
 
@@ -436,7 +478,6 @@
     (super-new)
     (show-macro-hiding-panel (send/i config config<%> get-show-hiding-panel?))
     (show-extra-navigation (send/i config config<%> get-extra-navigation?))
-    ;;(refresh/move)
     ))
 
 (define (macro-stepper-widget/process-mixin %)
diff --git a/collects/macro-debugger/view/term-record.rkt b/collects/macro-debugger/view/term-record.rkt
index 25a6de2..969c49a 100644
--- a/collects/macro-debugger/view/term-record.rkt
+++ b/collects/macro-debugger/view/term-record.rkt
@@ -32,7 +32,7 @@
       (send/i stepper widget<%> get-step-displayer))
 
     ;; Data
-    
+
     (init-field [events #f])
 
     (init-field [raw-deriv #f])
@@ -52,19 +52,14 @@
     (define steps #f)
 
     ;; --
-    
+
     (define steps-position #f)
 
     (define/private (status msg)
       (send stepper change-status msg))
-    (define-syntax with-status
-      (syntax-rules ()
-        [(ws msg #:immediate . body)
-         (begin (send stepper change-status msg #t)
-                (begin0 (let () . body)))]
-        [(ws msg . body)
-         (begin (send stepper change-status msg)
-                (begin0 (let () . body)))]))
+    (define-syntax-rule (with-status msg . body)
+      (begin (send stepper change-status msg)
+             (begin0 (let () . body))))
 
     (super-new)
 
@@ -125,7 +120,7 @@
         (with-handlers ([(lambda (e) #t)
                          (lambda (e)
                            (set! raw-deriv-oops e))])
-          (with-status "Parsing expansion derivation" #:immediate
+          (with-status "Parsing expansion derivation"
             (set! raw-deriv
                   (parse-derivation
                    (events->token-generator events)))))))
@@ -135,7 +130,7 @@
       (unless (or deriv deriv-hidden?)
         (recache-raw-deriv!)
         (when raw-deriv
-          (with-status "Processing expansion derivation" #:immediate
+          (with-status "Processing expansion derivation"
             (let ([process (send/i stepper widget<%> get-preprocess-deriv)])
               (let ([d (process raw-deriv)])
                 (when (not d)
@@ -153,7 +148,7 @@
       (unless (or raw-steps raw-steps-oops)
         (recache-synth!)
         (when deriv
-          (with-status "Computing reduction steps" #:immediate
+          (with-status "Computing reduction steps"
             (let ([show-macro? (or (send/i stepper widget<%> get-show-macro?)
                                    (lambda (id) #t))])
               (with-handlers ([(lambda (e) #t)