Perhaps its a BAMF problem? Often some time after this happens unity will completely freeze and I have to restart gdm from a tty console. Here's an .xsession-errors file from one of those times. It shows lots of critical errors from BAMF.
** Attachment added: "xsession-errors" https://bugs.launchpad.net/ubuntu/+source/unity/+bug/758253/+attachment/2027425/+files/xsession-errors -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/758253 Title: unity-compiz develops focus problems and sends input to minimized windows -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
