Index: /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIMachineWindow.h
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIMachineWindow.h	(revision 50521)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIMachineWindow.h	(revision 50522)
@@ -56,4 +56,5 @@
 
     /* Public getters: */
+    ulong screenId() const { return m_uScreenId; }
     UIMachineView* machineView() const { return m_pMachineView; }
     UIMachineLogic* machineLogic() const { return m_pMachineLogic; }
Index: /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineLogicFullscreen.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineLogicFullscreen.cpp	(revision 50521)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineLogicFullscreen.cpp	(revision 50522)
@@ -336,13 +336,18 @@
 
 #ifdef Q_WS_MAC
-    /* Keep sync for machine-logic/window(s) in ML and next: */
+    /* On ML and later: */
     if (vboxGlobal().osRelease() > MacOSXRelease_Lion)
     {
         foreach (UIMachineWindow *pMachineWindow, machineWindows())
         {
+            /* Keep sync for machine-logic/window(s): */
             connect(pMachineWindow, SIGNAL(sigNotifyAboutNativeFullscreenDidEnter()),
                     this, SLOT(sltHandleNativeFullscreenDidEnter()));
             connect(pMachineWindow, SIGNAL(sigNotifyAboutNativeFullscreenDidExit()),
                     this, SLOT(sltHandleNativeFullscreenDidExit()));
+            /* Enter native fullscreen mode: */
+            if (darwinScreensHaveSeparateSpaces() || pMachineWindow->screenId() == 0)
+                if (!darwinIsInFullscreenMode(pMachineWindow))
+                    darwinToggleFullscreenMode(pMachineWindow);
         }
     }
@@ -373,9 +378,10 @@
 
 #ifdef Q_WS_MAC
-    /* Leave sync for machine-logic/window(s) in ML and next: */
+    /* On ML and later: */
     if (vboxGlobal().osRelease() > MacOSXRelease_Lion)
     {
         foreach (UIMachineWindow *pMachineWindow, machineWindows())
         {
+            /* Leave sync for machine-logic/window(s): */
             disconnect(pMachineWindow, SIGNAL(sigNotifyAboutNativeFullscreenDidEnter()),
                        this, SLOT(sltHandleNativeFullscreenDidEnter()));
Index: /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineWindowFullscreen.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineWindowFullscreen.cpp	(revision 50521)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineWindowFullscreen.cpp	(revision 50522)
@@ -73,16 +73,4 @@
 #endif /* Q_WS_MAC */
 
-#ifdef RT_OS_DARWIN
-void UIMachineWindowFullscreen::sltToggleNativeFullscreenMode()
-{
-    /* Make sure this method is only used for ML and next: */
-    AssertReturnVoid(vboxGlobal().osRelease() > MacOSXRelease_Lion);
-
-    /* Enter native fullscreen mode: */
-    if (!darwinIsInFullscreenMode(this))
-        darwinToggleFullscreenMode(this);
-}
-#endif /* RT_OS_DARWIN */
-
 void UIMachineWindowFullscreen::sltMachineStateChanged()
 {
@@ -146,7 +134,4 @@
         UICocoaApplication::instance()->registerToNativeNotification("NSWindowDidExitFullScreenNotification", this,
                                                                      UIMachineWindow::handleNativeNotification);
-        /* Asynchronously toggle fullscreen mode for every screen which requires it: */
-        if (darwinScreensHaveSeparateSpaces() || m_uScreenId == 0)
-            QTimer::singleShot(0, this, SLOT(sltToggleNativeFullscreenMode()));
     }
 #endif /* Q_WS_MAC */
Index: /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineWindowFullscreen.h
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineWindowFullscreen.h	(revision 50521)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineWindowFullscreen.h	(revision 50522)
@@ -51,9 +51,4 @@
 private slots:
 
-#ifdef RT_OS_DARWIN
-    /** Mac OS X: Toggles native fullscreen mode. */
-    void sltToggleNativeFullscreenMode();
-#endif /* RT_OS_DARWIN */
-
     /* Session event-handlers: */
     void sltMachineStateChanged();