I am on one of the 2 year old iMacs(with the dome base) running 10.3.9 and my numerical keyboard just stopped working. First thing I did after pressing every key on the keyboard was to switch keyboards with another white keyboard (numerical keys worked on it when attached to another computer), but it still doesn't work. Went to online help which brilliantly said to "unlock the numerical keyboard lock" yeah.. well which key is that! My keyboard doesn't have the num lock on it, so that didn't help. Someone told me it was the clear key. Tried it, no change. I found a post from this site from 2 years ago and the person said he pressed the alt key 5 times and that fixed it. Well, that didn't work for me. The numerical keyboard does not work in any software program...I tried it with the calculator, Microsoft Word, Excel, Photoshop, Illustrator... doesn't work! Anyone out there that can help me?