diff --git a/collects/framework/splash.rkt b/collects/framework/splash.rkt
index 9bb519ec57..3edea6e37b 100644
--- a/collects/framework/splash.rkt
+++ b/collects/framework/splash.rkt
@@ -286,7 +286,7 @@
     (define/augment (on-close)
       (when quit-on-close?
         (exit)))
-    (super-new)))
+    (super-new [style '(close-button)])))
 
 (define splash-canvas%
   (class canvas%
diff --git a/collects/mred/private/mrtop.rkt b/collects/mred/private/mrtop.rkt
index c107cfb154..a290834db2 100644
--- a/collects/mred/private/mrtop.rkt
+++ b/collects/mred/private/mrtop.rkt
@@ -237,7 +237,7 @@
 	  (check-label-string cwho label)
 	  (check-top-level-parent/false cwho parent)
 	  (for-each (lambda (x) (check-dimension cwho x)) (list width height x y))
-	  (check-style cwho #f '(no-caption resize-border no-sheet) style)))
+	  (check-style cwho #f '(no-caption resize-border no-sheet close-button) style)))
       (rename [super-on-subwindow-char on-subwindow-char])
       (private-field [wx #f])
       (override
diff --git a/collects/mred/private/wx/cocoa/frame.rkt b/collects/mred/private/wx/cocoa/frame.rkt
index 58ec55651b..79e5c6a3a6 100644
--- a/collects/mred/private/wx/cocoa/frame.rkt
+++ b/collects/mred/private/wx/cocoa/frame.rkt
@@ -167,7 +167,9 @@
                                                               NSTitledWindowMask
                                                               (if is-sheet? NSUtilityWindowMask 0)
                                                               (if is-dialog?
-                                                                  0
+                                                                  (if (memq 'close-button style)
+                                                                      NSClosableWindowMask
+                                                                      0)
                                                                   (bitwise-ior 
                                                                    NSClosableWindowMask
                                                                    NSMiniaturizableWindowMask
@@ -190,7 +192,7 @@
          (tellv tb setVisible: #:type _BOOL #f)
          (tellv tb release))))
 
-    (move -11111 (if (= y -11111) 0 y))
+    (internal-move -11111 (if (= y -11111) 0 y))
 
     (tellv cocoa setAcceptsMouseMovedEvents: #:type _BOOL #t)
 
@@ -415,7 +417,7 @@
 
     (define/override (set-size x y w h)
       (unless (and (= x -1) (= y -1))
-        (move x y))
+        (internal-move x y))
       (let ([f (tell #:type _NSRect cocoa frame)])
         (tellv cocoa setFrame: 
                #:type _NSRect (make-NSRect 
@@ -436,7 +438,7 @@
                                                    (NSSize-height (NSRect-size f)))))
                                (make-NSSize w h))
                display: #:type _BOOL #t)))
-    (define/override (move x y)
+    (define/override (internal-move x y)
       (let ([x (if (= x -11111) (get-x) x)]
             [y (if (= y -11111) (get-y) y)])
         (tellv cocoa setFrameTopLeftPoint: #:type _NSPoint (make-NSPoint x (- (flip-screen y)
diff --git a/collects/mred/private/wx/cocoa/procs.rkt b/collects/mred/private/wx/cocoa/procs.rkt
index 77866d045d..a6caa39307 100644
--- a/collects/mred/private/wx/cocoa/procs.rkt
+++ b/collects/mred/private/wx/cocoa/procs.rkt
@@ -91,10 +91,15 @@
 (define (check-for-break) #f)
 
 (define (display-origin xb yb all?)
-  (set-box! xb 0)
   (if all?
-      (set-box! yb 0)
-      (set-box! yb (get-menu-bar-height))))
+      (atomically
+       (with-autorelease
+        (let* ([screen (tell (tell NSScreen screens) objectAtIndex: #:type _NSUInteger 0)]
+               [f (tell #:type _NSRect screen visibleFrame)])
+          (set-box! xb (->long (NSPoint-x (NSRect-origin f)))))))
+      (set-box! xb 0))
+  (set-box! yb (get-menu-bar-height)))
+
 (define (display-size xb yb all?)
   (atomically
    (with-autorelease
diff --git a/collects/mred/private/wx/cocoa/window.rkt b/collects/mred/private/wx/cocoa/window.rkt
index a76e56fe3a..a23a7a7295 100644
--- a/collects/mred/private/wx/cocoa/window.rkt
+++ b/collects/mred/private/wx/cocoa/window.rkt
@@ -520,8 +520,10 @@
         (tellv cocoa setNeedsDisplay: #:type _BOOL #t)
         (tellv cocoa setFrame: #:type _NSRect (make-NSRect (make-NSPoint x (flip y h))
                                                            (make-NSSize w h)))))
-    (define/public (move x y)
+    (define/public (internal-move x y)
       (set-size x y (get-width) (get-height)))
+    (define/public (move x y)
+      (internal-move x y))
 
     (define accept-drag? #f)
     (define accept-parent-drag? #f)
diff --git a/collects/mred/private/wxtop.rkt b/collects/mred/private/wxtop.rkt
index a0858c4816..c1fd3e71a6 100644
--- a/collects/mred/private/wxtop.rkt
+++ b/collects/mred/private/wxtop.rkt
@@ -90,7 +90,7 @@
        [panel #f]
 
        [use-default-position? (and (= -11111 (list-ref args 2))
-				   (= -11111 (list-ref args (if dlg? 3 1))))]
+                                   (= -11111 (list-ref args (if dlg? 3 1))))]
        
        [enabled? #t]
        [focus #f]
diff --git a/collects/scribblings/gui/dialog-class.scrbl b/collects/scribblings/gui/dialog-class.scrbl
index 98f5e55dd6..15df432952 100644
--- a/collects/scribblings/gui/dialog-class.scrbl
+++ b/collects/scribblings/gui/dialog-class.scrbl
@@ -16,7 +16,9 @@ A dialog is a top-level window that is @defterm{modal}: while the
                  [height (or/c (integer-in 0 10000) false/c) #f]
                  [x (or/c (integer-in 0 10000) false/c) #f]
                  [y (or/c (integer-in 0 10000) false/c) #f]
-                 [style (listof (one-of/c 'no-caption 'resize-border 'no-sheet)) null]
+                 [style (listof (one-of/c 'no-caption 'resize-border 
+                                          'no-sheet 'close-button)) 
+                        null]
                  [enabled any/c #t]
                  [border (integer-in 0 1000) 0]
                  [spacing (integer-in 0 1000) 0]
@@ -68,6 +70,9 @@ The @scheme[style] flags adjust the appearance of the dialog on some
  @item{@scheme['no-sheet] --- uses a movable window for the dialog,
  even if a parent window is provided (Mac OS X)}
 
+ @item{@scheme['close-button] --- include a close button in the 
+ dialog's title bar, which would not normally be included (Mac OS X)}
+
 ]
 
 Even if the dialog is not shown, a few notification events may be