Slimline aluminum keybd some keys don't work


The title says it all, the numbers row, starting with the "~"key to the number 5 or 6 do not register on the screen when pressed.
It has a new battery, the keyboard is only 2 years old (+-),
nothing has been spilled on it nor has it been dropped or abused.

I plugged in the original keyboard, the long one, which is great but my workspace is very limited which is why I bought the small keyboard.

Intel duo iMac 24", 10.7 OS X, 2GHZ, 4GB RAM, 500GB HD

Thanks for any help, views, solutions.