Certain letters stop working momentarily on desktop keyboard

Hello! I've had a "malfunctioning" keyboard for a long time (Microsoft Comfort Curve Keyboard 2000 v1.0) and the problem, that comes and goes, is that certain keys suddenly stop working and then after a while starts working flawlessly again. The weird part is that a while back it was the Q-key and some other one I don't remember, but now it's mainly the S, N and Å-button (swedish keyboard, its one-two steps right and one step down from 0). I've updated to the latest drivers several times and nothing seems to work, I know I can buy a new keyboard, but I rather not...

Any ideas?

Thanks!