Do you have the `desktop-effects` plugin installed? It adds a GUI option to the Preferences dropdown to replace metacity with compiz using the command `compiz.real --replace --use-cow gconf gconf`.
-- crash when launching compiz --replace and moving a window https://launchpad.net/bugs/73814 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
