diff --git a/collects/stepper/private/annotate.ss b/collects/stepper/private/annotate.ss
index 070d8520ba..3c201cb136 100644
--- a/collects/stepper/private/annotate.ss
+++ b/collects/stepper/private/annotate.ss
@@ -1146,6 +1146,8 @@
   
   (define (annotate/module-top-level exp)
     (cond [(stepper-syntax-property exp 'stepper-skip-completely) exp]
+          ;; for kathy's test engine:
+          [(syntax-property exp 'test-call) exp]
           [(stepper-syntax-property exp 'stepper-define-struct-hint)
            #`(begin #,exp
                     (#,(make-define-struct-break exp)))]
diff --git a/collects/stepper/private/macro-unwind.ss b/collects/stepper/private/macro-unwind.ss
index ecee85f13f..8e59593e3d 100644
--- a/collects/stepper/private/macro-unwind.ss
+++ b/collects/stepper/private/macro-unwind.ss
@@ -4,6 +4,7 @@
            mzlib/contract
 	   "model-settings.ss"
            "shared.ss"
+           #;(file "/Users/clements/clements/scheme-scraps/eli-debug.ss")
            (for-syntax scheme/base))
 
   (provide/contract [unwind (syntax? render-settings? . -> . syntax?)])
@@ -139,7 +140,7 @@
                                          (if define-type
                                              (kernel:kernel-syntax-case 
                                               unwound-body #f
-                                              [(#%plain-lambda arglist lam-body ...)
+                                              [(lambda arglist lam-body ...)
                                                (case define-type
                                                  [(shortened-proc-define)
                                                   (let ([proc-define-name
@@ -243,6 +244,8 @@
                    (syntax-case stx (if begin)
                      ;; the else clause disappears when it's a
                      ;; language-inserted else clause
+                     [(if test result)
+                      (list (unwind-cond-clause stx #`test #`result settings))]                     
                      [(if test result else-clause)
                       (cons (unwind-cond-clause stx #`test #`result settings)
                             (loop (syntax else-clause)))]
diff --git a/collects/stepper/private/model.ss b/collects/stepper/private/model.ss
index 3ce34ac1e8..9e2531bcf3 100644
--- a/collects/stepper/private/model.ss
+++ b/collects/stepper/private/model.ss
@@ -66,13 +66,15 @@
         boolean?                        ; track-inferred-names?
         (or/c object? (symbols 'testing))   ;; FIXME: can do better: subclass of language%       ; the language level
         (procedure? . -> . void?)       ; run-on-drscheme-side
+        boolean?                        ; disable-error-handling (to allow debugging)
         . -> .
         void?)])
 
   ; go starts a stepper instance
   ; see provide stmt for contract
   (define (go program-expander receive-result render-settings
-              show-lambdas-as-lambdas? language-level run-on-drscheme-side)
+              show-lambdas-as-lambdas? language-level run-on-drscheme-side
+              disable-error-handling)
 
     ;; finished-exps:
     ;;   (listof (list/c syntax-object? (or/c number? false?)( -> any)))
@@ -104,7 +106,7 @@
     ;;   whole be highlighted.  Is either one "wrong?"  equivalences between
     ;;   reduction semantics?
     ;;
-    ;; 2005-11-14: punting. just highlight the whole damn thing if there are
+    ;; 2005-11-14: punting. just highlight the whole darn thing if there are
     ;; any differences.  In fact, just test for eq?-ness.
 
     #;
@@ -311,10 +313,8 @@
 
     (program-expander
      (lambda ()
-       ;; swap these to allow errors to escape (e.g., when debugging)
-       #;(error-display-handler err-display-handler)
-       (void)
-       )
+       (unless disable-error-handling
+         (error-display-handler err-display-handler)))
      (lambda (expanded continue-thunk) ; iter
        (r:reset-special-values)
        (if (eof-object? expanded)
diff --git a/collects/stepper/stepper-tool.ss b/collects/stepper/stepper-tool.ss
index 3dd7207ec2..ac043e19ca 100644
--- a/collects/stepper/stepper-tool.ss
+++ b/collects/stepper/stepper-tool.ss
@@ -468,7 +468,8 @@
                               (send language-level stepper:enable-let-lifting?))
 	 (send language-level stepper:show-lambdas-as-lambdas?)
          language-level
-         run-on-drscheme-side)
+         run-on-drscheme-side
+         #f)
         (send s-frame show #t)
 
         s-frame)