Index: /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIMachineView.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIMachineView.cpp	(revision 43757)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIMachineView.cpp	(revision 43758)
@@ -918,4 +918,8 @@
         return true;
 
+    /* We should not process resize-event if parent window is hidden: */
+    if (!uisession()->isScreenVisible(m_uScreenId))
+        return true;
+
     /* Get guest resize-event: */
     UIResizeEvent *pResizeEvent = static_cast<UIResizeEvent*>(pEvent);