--- a/widget/src/cocoa/nsAppShell.h
+++ b/widget/src/cocoa/nsAppShell.h
@@ -76,11 +76,12 @@ protected:
   NSAutoreleasePool* mMainPool;
   CFMutableArrayRef  mAutoreleasePools;
 
   NSPort*            mPort;
   AppShellDelegate*  mDelegate;
 
   PRPackedBool       mRunningEventLoop;
   PRPackedBool       mTerminated;
+  PRPackedBool       mSkippedNativeCallback;
 };
 
 #endif // nsAppShell_h_

--- a/widget/src/cocoa/nsAppShell.mm
+++ b/widget/src/cocoa/nsAppShell.mm
@@ -69,27 +69,32 @@
 @end
 
 // nsAppShell implementation
 
 NS_IMETHODIMP
 nsAppShell::ResumeNative(void)
 {
   nsresult retval = nsBaseAppShell::ResumeNative();
-  if (NS_SUCCEEDED(retval) && (mSuspendNativeCount == 0))
+  if (NS_SUCCEEDED(retval) && (mSuspendNativeCount == 0) &&
+      mSkippedNativeCallback)
+  {
+    mSkippedNativeCallback = PR_FALSE;
     ScheduleNativeEventCallback();
+  }
   return retval;
 }
 
 nsAppShell::nsAppShell()
 : mAutoreleasePools(nsnull)
 , mPort(nil)
 , mDelegate(nil)
 , mRunningEventLoop(PR_FALSE)
 , mTerminated(PR_FALSE)
+, mSkippedNativeCallback(PR_FALSE)
 {
   // mMainPool sits low on the autorelease pool stack to serve as a catch-all
   // for autoreleased objects on this thread.  Because it won't be popped
   // until the appshell is destroyed, objects attached to this pool will
   // be leaked until app shutdown.  You probably don't want this!
   //
   // Objects autoreleased to this pool may result in warnings in the future.
   mMainPool = [[NSAutoreleasePool alloc] init];
@@ -199,18 +204,21 @@ nsAppShell::ProcessGeckoEvents()
                                     windowNumber:-1
                                          context:NULL
                                          subtype:0
                                            data1:0
                                            data2:0]
              atStart:NO];
   }
 
-  if (mSuspendNativeCount <= 0)
+  if (mSuspendNativeCount <= 0) {
     NativeEventCallback();
+  } else {
+    mSkippedNativeCallback = PR_TRUE;
+  }
 
   [NSApp postEvent:[NSEvent otherEventWithType:NSApplicationDefined
                                       location:NSMakePoint(0,0)
                                  modifierFlags:0
                                      timestamp:0
                                   windowNumber:-1
                                        context:NULL
                                        subtype:0

--- a/widget/src/mac/nsAppShell.cpp
+++ b/widget/src/mac/nsAppShell.cpp
@@ -55,25 +55,30 @@ enum {
 };
 
 // nsAppShell implementation
 
 NS_IMETHODIMP
 nsAppShell::ResumeNative(void)
 {
   nsresult retval = nsBaseAppShell::ResumeNative();
-  if (NS_SUCCEEDED(retval) && (mSuspendNativeCount == 0))
+  if (NS_SUCCEEDED(retval) && (mSuspendNativeCount == 0) &&
+      mSkippedNativeCallback)
+  {
+    mSkippedNativeCallback = PR_FALSE;
     ScheduleNativeEventCallback();
+  }
   return retval;
 }
 
 nsAppShell::nsAppShell()
 : mCFRunLoop(NULL)
 , mCFRunLoopSource(NULL)
 , mRunningEventLoop(PR_FALSE)
+, mSkippedNativeCallback(PR_FALSE)
 {
 }
 
 nsAppShell::~nsAppShell()
 {
   if (mCFRunLoopSource) {
     ::CFRunLoopRemoveSource(mCFRunLoop, mCFRunLoopSource,
                             kCFRunLoopCommonModes);
@@ -204,13 +209,16 @@ nsAppShell::ProcessGeckoEvents(void* aIn
                                  kEventAttributeNone, &bogusEvent);
     if (err == noErr) {
       ::PostEventToQueue(::GetMainEventQueue(), bogusEvent,
                          kEventPriorityStandard);
       ::ReleaseEvent(bogusEvent);
     }
   }
 
-  if (self->mSuspendNativeCount <= 0)
-    self->NativeEventCallback();
+  if (mSuspendNativeCount <= 0) {
+    NativeEventCallback();
+  } else {
+    mSkippedNativeCallback = PR_TRUE;
+  }
 
   NS_RELEASE(self);
 }

--- a/widget/src/mac/nsAppShell.h
+++ b/widget/src/mac/nsAppShell.h
@@ -74,11 +74,12 @@ protected:
 protected:
   nsCOMPtr<nsIToolkit>        mToolkit;
   nsAutoPtr<nsMacMessagePump> mMacPump;
 
   CFRunLoopRef                mCFRunLoop;
   CFRunLoopSourceRef          mCFRunLoopSource;
 
   PRBool                      mRunningEventLoop;
+  PRBool                      mSkippedNativeCallback;
 };
 
 #endif // nsAppShell_h__