diff --git a/collects/mred/private/wx/cocoa/dc.rkt b/collects/mred/private/wx/cocoa/dc.rkt
index 278d2cbbb5..2ecb3f477e 100644
--- a/collects/mred/private/wx/cocoa/dc.rkt
+++ b/collects/mred/private/wx/cocoa/dc.rkt
@@ -60,7 +60,12 @@
         (values (unbox xb) (unbox yb))))
 
     (define/override (queue-backing-flush)
-      ;; called atomically (not expecting exceptions)
+      ;; With Cocoa window-level delay doesn't stop
+      ;; displays; it blocks flushes to the screen.
+      ;; So leave the delay in place, and `end-delay'
+      ;; after displaying to the window (after which
+      ;; we'll be ready to flush the window), which
+      ;; is at then end of `do-backing-flush'.
       (send canvas queue-backing-flush))
 
     (define/override (request-delay)
@@ -92,6 +97,6 @@
                    (cairo_fill cr)
                    (cairo_set_source cr s)
                    (cairo_pattern_destroy s))
-                 (cairo_destroy cr))))))
-   (tellv ctx restoreGraphicsState)
-   (send dc end-delay)))
+                 (cairo_destroy cr))))
+           (send dc end-delay)))
+   (tellv ctx restoreGraphicsState)))
diff --git a/collects/mred/private/wx/gtk/dc.rkt b/collects/mred/private/wx/gtk/dc.rkt
index 01a141a255..5b223022b2 100644
--- a/collects/mred/private/wx/gtk/dc.rkt
+++ b/collects/mred/private/wx/gtk/dc.rkt
@@ -77,6 +77,7 @@
 (define dc%
   (class backing-dc%
     (init [(cnvs canvas)])
+    (inherit end-delay)
     (define canvas cnvs)
 
     (super-new)
@@ -102,7 +103,9 @@
         (values (unbox xb) (unbox yb))))
 
     (define/override (queue-backing-flush)
-      ;; called atomically (not expecting exceptions)
+      ;; Re-enable expose events so that the queued 
+      ;; backing flush will be handled:
+      (end-delay)
       (send canvas queue-backing-flush))
 
     (define/override (request-delay)
@@ -111,20 +114,18 @@
       (cancel-flush-delay req))))
 
 (define (do-backing-flush canvas dc win)
-  (begin0
-   (send dc on-backing-flush
-         (lambda (bm)
-           (let ([w (box 0)]
-                 [h (box 0)])
-             (send canvas get-client-size w h)
-             (let ([cr (gdk_cairo_create win)])
-               (let ([s (cairo_get_source cr)])
-                 (cairo_pattern_reference s)
-                 (cairo_set_source_surface cr (send bm get-cairo-surface) 0 0)
-                 (cairo_new_path cr)
-                 (cairo_rectangle cr 0 0 (unbox w) (unbox h))
-                 (cairo_fill cr)
-                 (cairo_set_source cr s)
-                 (cairo_pattern_destroy s))
-               (cairo_destroy cr)))))
-   (send dc end-delay)))
+  (send dc on-backing-flush
+        (lambda (bm)
+          (let ([w (box 0)]
+                [h (box 0)])
+            (send canvas get-client-size w h)
+            (let ([cr (gdk_cairo_create win)])
+              (let ([s (cairo_get_source cr)])
+                (cairo_pattern_reference s)
+                (cairo_set_source_surface cr (send bm get-cairo-surface) 0 0)
+                (cairo_new_path cr)
+                (cairo_rectangle cr 0 0 (unbox w) (unbox h))
+                (cairo_fill cr)
+                (cairo_set_source cr s)
+                (cairo_pattern_destroy s))
+              (cairo_destroy cr))))))