Index: /trunk/src/VBox/Frontends/VirtualBox/src/widgets/UIProgressDialog.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/widgets/UIProgressDialog.cpp	(revision 45334)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/widgets/UIProgressDialog.cpp	(revision 45335)
@@ -153,6 +153,17 @@
 #endif /* Q_WS_MAC */
 
-        /* Enter the modal loop, but don't show the window immediately */
-        exec(false);
+        /* Create a local event-loop: */
+        {
+            /* Guard ourself for the case
+             * we destroyed ourself in our event-loop: */
+            QPointer<UIProgressDialog> guard = this;
+
+            /* Enter the modal loop, but don't show the window immediately: */
+            exec(false);
+
+            /* Are we still valid? */
+            if (guard.isNull())
+                return Rejected;
+        }
 
         /* Kill refresh timer */