Extended keyboard number pad problem

My stock keyboard numb er pad does not work right. The "=", "/", "+", "-", "*" and "enter" keys work OK. The upper row sound and eject keys work OK

None of the digit keys work as expected. The "." key also does not work.

Hitting the zero digit key locks up my mouse button. Other keys give erratic results.

I have reset the keybaord preferences and reset PRAM many times with no benefit.

I have exactly the same results on both my wired keyboard and the B luetooth wireless Apple keyboard.

I have read other complaints very similar to mine but no solution.

Any ideas?

TIA,
Bill