So I have a laptop with a full keyboard including the number keypad. I'm running Kubuntu 11.10 and loving it but I noticed my number keypad isn't working. So I searched and searched, and it sounds like a joke, but this seriously does fix it lol.
Press the following at the same time once:
Now it works. I hope this helped someone, because I just fixed it this way for myself so I thought I would share.