Are you using the open source ATI driver? If so, are you using EXA? This caused problems for me. If you're using EXA with _any_ driver try disabling it and see if that fixes things.
** Bug 30020 has been marked a duplicate of this bug -- Dapper Ubuntulooks: pressed buttons appear corrupted after windows are restored https://launchpad.net/bugs/42237 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
