i know that this seems to be a gnome bug, but i got the same issue within kubuntu 12.10
when activating the mouse focus policy "focus under mouse" or "focus strictly under mouse" in the windows property settings alt+tab stops working. using any other focus policy enables alt+tab again. maybe this information might help to fix the gnome issue -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-panel in Ubuntu. https://bugs.launchpad.net/bugs/971051 Title: no alt+tab in gnome classic session To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/971051/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs