--- old/src/macosx/native/sun/awt/AWTWindow.m	2013-06-05 14:48:23.509362800 +0400
+++ new/src/macosx/native/sun/awt/AWTWindow.m	2013-06-05 14:48:22.941330300 +0400
@@ -539,7 +539,7 @@
     AWTWindow *opposite = [AWTWindow lastKeyWindow];
     if (!IS(self.styleBits, IS_DIALOG)) {
         [CMenuBar activate:self.javaMenuBar modallyDisabled:NO];
-    } else if (IS(self.styleBits, IS_MODAL)) {
+    } else if ((opposite != NULL) && IS(self.styleBits, IS_MODAL)) {
         [CMenuBar activate:opposite->javaMenuBar modallyDisabled:YES];        
     }
     [AWTWindow setLastKeyWindow:nil];