Product Version: NetBeans IDE Dev (Build 201206110001)
Java: 1.7.0_05; Java HotSpot(TM) 64-Bit Server VM 23.1-b03
System: Mac OS X version 10.7.4 running on x86_64; US-ASCII; en_US (nb)

Primary screen is my macbook, secondary is LCD, positioned above.
Moved IDE to external monitor and invoking popup in editor repeatedly:
~50% of popups are not rendered corerctly. See couple of attached screenshot
what I mean by "not rendered correctly":

http://bugzilla-attachments-213988.netbeans.org/bugzilla/attachment.cgi?id=120678
http://bugzilla-attachments-213988.netbeans.org/bugzilla/attachment.cgi?id=120679
http://bugzilla-attachments-213988.netbeans.org/bugzilla/attachment.cgi?id=120680

The original NetBeans bug:
http://netbeans.org/bugzilla/show_bug.cgi?id=213988