Index: /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin-cocoa.mm
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin-cocoa.mm	(revision 80695)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin-cocoa.mm	(revision 80696)
@@ -27,4 +27,5 @@
 #import <AppKit/NSFont.h>
 #import <AppKit/NSScreen.h>
+#import <AppKit/NSScroller.h>
 #import <AppKit/NSWindow.h>
 #import <AppKit/NSImageView.h>
@@ -261,4 +262,17 @@
     if ([NSScreen respondsToSelector: @selector(screensHaveSeparateSpaces)])
         return [NSScreen performSelector: @selector(screensHaveSeparateSpaces)];
+    else
+        return false;
+}
+
+bool darwinIsScrollerStyleOverlay()
+{
+    /* Check whether scrollers by default have legacy style.
+     * This method is available since 10.7 only. */
+    if ([NSScroller respondsToSelector: @selector(preferredScrollerStyle)])
+    {
+        const int enmType = (int)(intptr_t)[NSScroller performSelector: @selector(preferredScrollerStyle)];
+        return enmType == NSScrollerStyleOverlay;
+    }
     else
         return false;
Index: /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.h
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.h	(revision 80695)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/platform/darwin/VBoxUtils-darwin.h	(revision 80696)
@@ -115,4 +115,5 @@
 SHARED_LIBRARY_STUFF bool darwinIsOnActiveSpace(NativeNSWindowRef pWindow);
 SHARED_LIBRARY_STUFF bool darwinScreensHaveSeparateSpaces();
+SHARED_LIBRARY_STUFF bool darwinIsScrollerStyleOverlay();
 
 bool darwinOpenFile(NativeNSStringRef pstrFile);
Index: /trunk/src/VBox/Frontends/VirtualBox/src/widgets/graphics/UIGraphicsScrollArea.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/widgets/graphics/UIGraphicsScrollArea.cpp	(revision 80695)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/widgets/graphics/UIGraphicsScrollArea.cpp	(revision 80696)
@@ -23,4 +23,7 @@
 #include "UIGraphicsScrollArea.h"
 #include "UIGraphicsScrollBar.h"
+#ifdef VBOX_WS_MAC
+# include "VBoxUtils.h"
+#endif
 
 
@@ -245,4 +248,9 @@
 void UIGraphicsScrollArea::prepareWidgets()
 {
+#ifdef VBOX_WS_MAC
+    /* Check whether scroll-bar is in auto-hide (overlay) mode: */
+    m_fAutoHideMode = darwinIsScrollerStyleOverlay();
+#endif
+
     /* Create scroll-bar: */
     m_pScrollBar = new UIGraphicsScrollBar(m_enmOrientation, m_fAutoHideMode, this);