I had that problem... have you tried removing all the problem keys and checking theyre not gunged up or anything. I had to get a new keyb when it happened to me, as trying to fix it made my "6" key jam on when i pressed u, i, j, k, m and ,
Jusdging by the fact those keys are next to the ones that are randomly being pressed, i sounds like youve got to have something under them, or its screwed up and a new one is the only option