Normally I use alt+left key combo to go back one click in firefox but recently I noticed it's moving to vt6 instead. alt+right moves in the other direction among the vt screens. This is supposed to be disabled when X is running. Where is this configured and how do I turn it off?
Edit: I just tried out running a guest user session, and alt-left doesn't do this in unity. So this is probably something to do with my specific user, or metacity.