First off, there’s an easy workaround for it. Go into the Keyboard Preferences (System >Preferences > Keyboard) and go to the Mouse Keys tab. Simply uncheck the box for Allow to control the pointer using the keyboard. (I know the grammar sucks on that sentence. I need to find a bug for that as well.) That will let users of Ubuntu Hardy, and other distros that use GNOME 2.22, to regain the use of their numeric keypad.