diff --git a/collects/macro-debugger/model/deriv-c.ss b/collects/macro-debugger/model/deriv-c.ss
index bc494c6..c7113c4 100644
--- a/collects/macro-debugger/model/deriv-c.ss
+++ b/collects/macro-debugger/model/deriv-c.ss
@@ -17,7 +17,7 @@
   ;; - resolves is the list of identifiers resolved by the macro keyword
   ;; - me1 is the marked version of the input syntax
   ;; - me2 is the marked version of the output syntax
-  (define-struct transformation (e1 e2 resolves me1 me2 locals) #f)
+  (define-struct transformation (e1 e2 resolves me1 me2 locals seq) #f)
 
   ;; A LocalAction is one of
   ;;  - (make-local-expansion Syntax Syntax Syntax Syntax Derivation)
diff --git a/collects/macro-debugger/model/deriv-parser.ss b/collects/macro-debugger/model/deriv-parser.ss
index 7b528d1..393aba6 100644
--- a/collects/macro-debugger/model/deriv-parser.ss
+++ b/collects/macro-debugger/model/deriv-parser.ss
@@ -13,8 +13,18 @@
         (error 'derivation-parser "bad token #~a" start)))
   
   ;; PARSER
+
+  (define (parse-derivation x)
+    (parameterize ((current-sequence-number 0))
+      (parse-derivation* x)))
+
+  (define current-sequence-number (make-parameter #f))
+  (define (new-sequence-number)
+    (let ([seq (current-sequence-number)])
+      (current-sequence-number (add1 seq))
+      seq))
   
-  (define parse-derivation
+  (define parse-derivation*
     (parser
      (options (start Expansion)
               (src-pos)
@@ -132,7 +142,7 @@
          (! 'bad-transformer)
          macro-pre-transform (? LocalActions 'locals) (! 'transform) macro-post-transform 
          exit-macro)
-        (make-transformation $2 $8 $1 $4 $7 $5)])
+        (make-transformation $2 $8 $1 $4 $7 $5 (new-sequence-number))])
 
       ;; Local actions taken by macro
       ;; LocalAction Answer = (list-of LocalAction)
@@ -373,7 +383,7 @@
        ;; let*-values with bindings is "macro-like"
        [(prim-let*-values ! (? EE))
         (let ([next-e1 (lift/deriv-e1 $3)])
-          (make-mrule e1 e2 (make-transformation e1 next-e1 rs e1 next-e1 null) $3))]
+          (make-mrule e1 e2 (make-transformation e1 next-e1 rs e1 next-e1 null (new-sequence-number)) $3))]
        ;; No bindings... model as "let"
        [(prim-let*-values NoError renames-let (? NextEEs 'rhss) next-group (? EB 'body))
         (make-p:let-values e1 e2 rs $3 $4 $6)])
diff --git a/collects/macro-debugger/model/deriv-util.ss b/collects/macro-debugger/model/deriv-util.ss
index 35e9e9a..242a794 100644
--- a/collects/macro-debugger/model/deriv-util.ss
+++ b/collects/macro-debugger/model/deriv-util.ss
@@ -156,7 +156,7 @@
          (join (loop tx) (loop next))]
         [(AnyQ lift-deriv (_ _ first lift second))
          (join (loop first) (loop lift) (loop second))]
-        [(AnyQ transformation (_ _ _ _ _ locals))
+        [(AnyQ transformation (_ _ _ _ _ locals _))
          (loops locals)]
         [(struct local-expansion (_ _ _ _ deriv))
          (loop deriv)]
diff --git a/collects/macro-debugger/model/reductions.ss b/collects/macro-debugger/model/reductions.ss
index 673987c..2ac6e99 100644
--- a/collects/macro-debugger/model/reductions.ss
+++ b/collects/macro-debugger/model/reductions.ss
@@ -284,14 +284,14 @@
   ;; reductions-transformation : Transformation -> ReductionSequence
   (define (reductions-transformation tx)
     (match tx
-      [(struct transformation (e1 e2 rs me1 me2 locals))
+      [(struct transformation (e1 e2 rs me1 me2 locals seq))
        (append (reductions-locals e1 locals)
                (list (walk e1 e2 'macro-step)))]
-      [(IntW transformation (e1 e2 rs me1 me2 locals) 'locals)
+      [(IntW transformation (e1 e2 rs me1 me2 locals seq) 'locals)
        (reductions-locals e1 locals)]
-      [(ErrW transformation (e1 e2 rs me1 me2 locals) 'bad-transformer exn)
+      [(ErrW transformation (e1 e2 rs me1 me2 locals seq) 'bad-transformer exn)
        (list (stumble e1 exn))]
-      [(ErrW transformation (e1 e2 rs me1 me2 locals) 'transform exn)
+      [(ErrW transformation (e1 e2 rs me1 me2 locals seq) 'transform exn)
        (append (reductions-locals e1 locals)
                (list (stumble e1 exn)))]))
 
diff --git a/collects/macro-debugger/view/hiding-panel.ss b/collects/macro-debugger/view/hiding-panel.ss
index 146154a..5558d92 100644
--- a/collects/macro-debugger/view/hiding-panel.ss
+++ b/collects/macro-debugger/view/hiding-panel.ss
@@ -101,11 +101,11 @@
       ;; refresh
       (define/public (refresh)
         (when (send config get-macro-hiding?)
-          (send stepper refresh/resynth)))
+          (send stepper refresh)))
 
       ;; force-refresh
       (define/private (force-refresh)
-        (send stepper refresh/resynth))
+        (send stepper refresh/resynth-prefix))
       
       ;; set-syntax : syntax/#f -> void
       (define/public (set-syntax lstx)