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 Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/609202 Title: Some mouse key bindings don't change correctly -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
