Comment 5 for bug 1064898

Looking at the screenshot I bet this is the same bug as https://bugs.launchpad.net/ubuntu/+source/gnome-session/+bug/1036752

To verify, after logging into the normal Gnome Classic session, check ~/.xsession-errors and see if only the 'core' and 'ccp' compiz plugins are loaded. If so you can workaround the issue by using compizconfig-settings-manager to enable a minimal set of plugins, or just use the (no effects) session until the issue is fixed.