diff --git a/collects/drscheme/private/unit.ss b/collects/drscheme/private/unit.ss
index c389d4204c..ef5609910d 100644
--- a/collects/drscheme/private/unit.ss
+++ b/collects/drscheme/private/unit.ss
@@ -1247,7 +1247,9 @@ module browser threading seems wrong.
           (update-execute-warning-gui))
         (define/public (update-execute-warning-gui)
           (when (is-current-tab?)
-            (send frame show/hide-warning-message (get-current-execute-warning))))
+            (send frame show/hide-warning-message 
+                  (get-current-execute-warning)
+                  (λ () (clear-execution-state)))))
         
         (define/public (get-directory)
           (let ([filename (send defs get-filename)])
@@ -1424,7 +1426,7 @@ module browser threading seems wrong.
         (define execute-warning-panel #f)
         (define execute-warning-parent-panel #f)
         (define execute-warning-canvas #f)
-        (define/public-final (show/hide-warning-message msg)
+        (define/public-final (show/hide-warning-message msg hide-canvas)
           (when (and execute-warning-parent-panel
                      execute-warning-panel)
             (cond
@@ -1435,8 +1437,13 @@ module browser threading seems wrong.
                  [else
                   (set! execute-warning-canvas
                         (new execute-warning-canvas% 
+                             [stretchable-height #t]
                              [parent execute-warning-panel]
-                             [message msg]))])
+                             [message msg]))
+                  (new close-icon% 
+                       [parent execute-warning-panel]
+                       [bg-color "yellow"]
+                       [callback (λ () (hide-canvas))])])
                (send execute-warning-parent-panel
                      change-children
                      (λ (l) (append (remq execute-warning-panel l)
@@ -1779,7 +1786,7 @@ module browser threading seems wrong.
             (send logger-parent-panel change-children (lambda (x) (remq logger-panel x)))
             
             (set! execute-warning-parent-panel execute-warning-outer-panel)
-            (set! execute-warning-panel (new vertical-panel% 
+            (set! execute-warning-panel (new horizontal-panel% 
                                              [parent execute-warning-parent-panel]
                                              [stretchable-height #f]))
             (send execute-warning-parent-panel change-children (λ (l) (remq execute-warning-panel l)))
@@ -4069,6 +4076,7 @@ module browser threading seems wrong.
         (inherit stretchable-height get-dc get-client-size min-height)
         (init-field message)
         (define/public (set-message _msg) (set! message _msg))
+        
         (define/override (on-paint)
           (let ([dc (get-dc)])
             (let-values ([(w h) (get-client-size)])
@@ -4095,7 +4103,6 @@ module browser threading seems wrong.
                         (floor (- (/ w 2) (/ tw 2)))
                         (floor (- (/ h 2) (/ th 2)))))))))
         (super-new)
-        (stretchable-height #f)
         (let-values ([(w h d a) (send (get-dc) get-text-extent "Xy")])
           (min-height (+ 4 (floor (inexact->exact h)))))))
     
diff --git a/collects/mrlib/close-icon.ss b/collects/mrlib/close-icon.ss
index 24e05a0c1b..cde9e95fbc 100644
--- a/collects/mrlib/close-icon.ss
+++ b/collects/mrlib/close-icon.ss
@@ -55,7 +55,8 @@
   (class canvas%
     (inherit get-dc min-width min-height stretchable-width stretchable-height
              get-client-size refresh)
-    (init-field [callback void])
+    (init-field [callback void]
+                [bg-color #f])
     (init [horizontal-pad 4]
           [vertical-pad 4])
     (init-masks)
@@ -92,6 +93,11 @@
     (define/override (on-paint)
       (let ([dc (get-dc)])
         (let-values ([(cw ch) (get-client-size)])
+          (when bg-color
+            (send dc set-brush bg-color 'solid)
+            (send dc set-pen bg-color 1 'transparent)
+            (let-values ([(w h) (get-client-size)])
+              (send dc draw-rectangle 0 0 w h)))
           (send dc draw-bitmap icon 
                 (- (/ cw 2) (/ (send icon get-width) 2))
                 (- (/ ch 2) (/ (send icon get-height) 2))
diff --git a/collects/mrlib/scribblings/close-icon.scrbl b/collects/mrlib/scribblings/close-icon.scrbl
index 2a62dd243c..0d5e3616e7 100644
--- a/collects/mrlib/scribblings/close-icon.scrbl
+++ b/collects/mrlib/scribblings/close-icon.scrbl
@@ -13,8 +13,11 @@ provides a clickable close button icon.}
 @defclass[close-icon% canvas% ()]{
  @defconstructor[([parent (is-a? area-container<%>)]
                   [callback (-> any) void]
+                  [bg-color (or/c #f string (is-a?/c color%))]
                   [horizontal-pad positive-integer? 4]
                   [vertical-pad positive-integer? 4])]{
    The @scheme[callback] is called when the close icon is clicked.
+       
+   If @scheme[bg-color] is specified, it is used as the background color of the icon.
  }
 }