I'll second the fix put forward by madchicken - Option "XAANoOffscreenPixmaps" clears up the problem for me as well.
-- Cairo and ATI RENDER extension cause scrambled buttons in UbuntuLooks https://launchpad.net/bugs/34435 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs