diff --git a/collects/drracket/private/init.rkt b/collects/drracket/private/init.rkt
index 8bee64b9ab..2f3bad817b 100644
--- a/collects/drracket/private/init.rkt
+++ b/collects/drracket/private/init.rkt
@@ -31,24 +31,65 @@
   
   (define system-security-guard (current-security-guard))
   
+  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+  ;;
+  ;;  internal error display support
+  ;;
+  
+  (define error-display-chan (make-channel))
+  (thread
+   (λ () 
+     (define-struct recent (msg when))
+     (define currently-visible-chan (make-channel))
+     (let loop ([recently-seen-errors/unfiltered '()]
+                [currently-visible #f])
+       (sync
+        (handle-evt
+         error-display-chan
+         (λ (msg+exn)
+           (define recently-seen-errors 
+             ;; recent errors are ones less than 5 minutes old
+             (let ([now (current-seconds)])
+               (filter (λ (x) (<= (+ (recent-when x) (* 60 5)) now))
+                       recently-seen-errors/unfiltered)))
+           (define-values (msg exn) (apply values msg+exn))
+           (cond
+             [currently-visible 
+              ;; drop errors when we have one waiting to be clicked on
+              (loop recently-seen-errors #t)]
+             [(ormap (λ (x) (equal? msg (recent-msg x))) 
+                     recently-seen-errors)
+              ;; drop the error if we've seen it recently
+              (loop recently-seen-errors #f)]
+             [else
+              ;; show the error
+              (define title (error-display-handler-message-box-title))
+              (define text (let ([p (open-output-string)])
+                             (parameterize ([current-error-port p]
+                                            [current-output-port p])
+                               (original-error-display-handler msg exn))
+                             (get-output-string p)))
+              
+              (parameterize ([current-eventspace error-display-eventspace]
+                             [current-custodian system-custodian])
+                (thread
+                 (λ () 
+                   (message-box title text #f '(stop ok) #:dialog-mixin frame:focus-table-mixin)
+                   (channel-put currently-visible #f))))
+              (loop (cons (make-recent msg (current-seconds)) recently-seen-errors)
+                    #t)])))
+        (handle-evt
+         currently-visible-chan
+         (λ (val) 
+           (loop recently-seen-errors/unfiltered #f)))))))
+  
   ;; override error-display-handler to duplicate the error
   ;; message in both the standard place (as defined by the
   ;; current error-display-handler) and in a message box
   ;; identifying the error as a drscheme internal error.
   (error-display-handler
    (λ (msg exn)
-     
      ;; this  may raise an exception if the port is gone.
      (with-handlers ([exn:fail? (λ (x) (void))])
        (original-error-display-handler msg exn))
-     
-     (let ([title (error-display-handler-message-box-title)])
-       (let ([text (let ([p (open-output-string)])
-                     (parameterize ([current-error-port p]
-                                    [current-output-port p])
-                       (original-error-display-handler msg exn))
-                     (get-output-string p))])
-         
-         (parameterize ([current-custodian system-custodian])
-           (parameterize ([current-eventspace error-display-eventspace])
-             (message-box title text #f '(stop ok) #:dialog-mixin frame:focus-table-mixin)))))))
+     (channel-put error-display-chan (list msg exn))))