So I've realized what has happened. The tooltip is larger than your video card's max texture size so compiz aborts and launches metacity because the only other option would be for you to see a blank white window as there is no way for compiz to show that window.
** Changed in: compiz (Ubuntu) Status: New => Won't Fix -- Compiz borks when tooltips are wider than screen https://bugs.launchpad.net/bugs/567025 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs