diff --git a/collects/mred/private/moredialogs.rkt b/collects/mred/private/moredialogs.rkt
index 3f9b1fc5..8f275043 100644
--- a/collects/mred/private/moredialogs.rkt
+++ b/collects/mred/private/moredialogs.rkt
@@ -208,7 +208,7 @@
 								    ((done #t) #f #f)))
 			      init-val (list* 'single 'vertical-label style))]
 	      [p (make-object horizontal-pane% f)])
-	  (send p set-alignment 'right 'center)
+          (send p set-alignment 'right 'center)
 	  (send f stretchable-height #f)
           (ok-cancel
            (lambda () (make-object button% "OK" p (done #t) '(border)))
diff --git a/collects/mred/private/wx/cocoa/dialog.rkt b/collects/mred/private/wx/cocoa/dialog.rkt
index 2e696629..a07fc383 100644
--- a/collects/mred/private/wx/cocoa/dialog.rkt
+++ b/collects/mred/private/wx/cocoa/dialog.rkt
@@ -28,7 +28,7 @@
         (let ([s (atomically
                   (let ([s (or close-sema (make-semaphore))])
                     (unless close-sema (set! close-sema s))
-                    s))])
+                    (semaphore-peek-evt s)))])
           (super show on?)
           (yield s)
           (void))
diff --git a/collects/mred/private/wx/common/queue.rkt b/collects/mred/private/wx/common/queue.rkt
index 2f52f60a..f76205bf 100644
--- a/collects/mred/private/wx/common/queue.rkt
+++ b/collects/mred/private/wx/common/queue.rkt
@@ -355,7 +355,7 @@
                             (when v (handle-event v))
                             (yield evt))))]
        [else
-        (sync e)]))]))
+        (sync evt)]))]))
 
 (define event-dispatch-handler (make-parameter void))
 (define (main-eventspace? e)
diff --git a/collects/mred/private/wx/gtk/dialog.rkt b/collects/mred/private/wx/gtk/dialog.rkt
index 3de209a7..6c063d65 100644
--- a/collects/mred/private/wx/gtk/dialog.rkt
+++ b/collects/mred/private/wx/gtk/dialog.rkt
@@ -3,6 +3,7 @@
          ffi/unsafe
           "../../syntax.rkt"
           "../common/queue.rkt"
+          "../../lock.rkt"
           "types.rkt"
           "utils.rkt"
           "frame.rkt")
@@ -51,9 +52,10 @@
     (unless on?
       (set! dialog-level 0))
     (unless on?
-      (when close-sema
-        (semaphore-post close-sema)
-        (set! close-sema #f)))
+      (atomically
+       (when close-sema
+         (semaphore-post close-sema)
+         (set! close-sema #f))))
     (super direct-show on?))
 
   (define/override (center dir wrt)
@@ -66,9 +68,11 @@
 
   (define/override (show on?)
     (if on?
-        (unless close-sema
-          (let ([s (make-semaphore)])
-            (set! close-sema s)
-            (super show on?)
-            (yield s)))
+        (let ([s (atomically
+                  (let ([s (or close-sema (make-semaphore))])
+                    (unless close-sema (set! close-sema s))
+                    (semaphore-peek-evt s)))])
+          (super show on?)
+          (yield s)
+          (void))
         (super show on?))))
diff --git a/collects/mred/private/wxme/text.rkt b/collects/mred/private/wxme/text.rkt
index e01fa2b4..42f2a300 100644
--- a/collects/mred/private/wxme/text.rkt
+++ b/collects/mred/private/wxme/text.rkt
@@ -4759,7 +4759,7 @@
 
                         (when (and resized? s-admin)
                           (send s-admin resized #f))
-                        
+
                         (on-reflow)))))))))))
 
   (def/public (on-reflow) (void))
diff --git a/collects/mred/private/wxtextfield.rkt b/collects/mred/private/wxtextfield.rkt
index b12ee9a8..f958b5a7 100644
--- a/collects/mred/private/wxtextfield.rkt
+++ b/collects/mred/private/wxtextfield.rkt
@@ -241,7 +241,7 @@
 
 	    ;; Exact
 	    (set! dy (inexact->exact dy))))
-	
+
 	(when value
 	  (set-value value)
 	  (unless (string=? value "")