This appears to be a conflict between gtk-window-decorator and compiz itself. if you kill the decorator, then Alt-Button3 acts as configured in compiz. gtk-window-decorator --minimal also seems to disable the key binding, but also disables the other decorations as well.
** Tags added: maverick -- You received this bug notification because you are a member of compiz packagers, which is subscribed to compiz in ubuntu. https://bugs.launchpad.net/bugs/609202 Title: Some mouse key bindings don't change correctly _______________________________________________ Mailing list: https://launchpad.net/~compiz Post to : compiz@lists.launchpad.net Unsubscribe : https://launchpad.net/~compiz More help : https://help.launchpad.net/ListHelp