BasicPopupMenuUI: MenuKeyboardHelper.uninstall() and MouseGrabber.uninstall() should be synchronized in jdk7 as it was done in 6u2.
There is a fix for 6492266. At first it was integrated into jdk7, then it was changed a bit and integrated into 6u2. The both fixes should be equal. The involved code in jdk7 should be made the same as it is in 6u2.

Webrevs for 6492266:
6u2 fix version: http://javaweb.sfbay/jcg/6u2/swing/6492266/
jdk7 fix version: http://javaweb.sfbay/jcg/1.7.0-dolphin/swing/6492266/