Index: /trunk/src/VBox/Frontends/VirtualBox/src/globals/UIMessageCenter.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/globals/UIMessageCenter.cpp	(revision 45536)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/globals/UIMessageCenter.cpp	(revision 45537)
@@ -279,5 +279,5 @@
 
     /* Create message-box: */
-    QWidget *pBoxParent = windowManager().realParentWindow(pParent);
+    QWidget *pBoxParent = windowManager().realParentWindow(pParent ? pParent : windowManager().mainWindowShown());
     QPointer<QIMessageBox> pBox = new QIMessageBox(strTitle, strMessage, icon,
                                                    iButton1, iButton2, iButton3, pBoxParent);