Can't pair apple wireless keyboard Keyboard: Apple Wireless Keyboard (model number MC184LL/B)

System: Macbook Pro Early 2011 running OS X 10.8

The keyboard gets detected and when I try to pair it, the system asks to enter some numbers through the keyboard. 

However when I press the key (on the wireless keyboard) nothing happens, the only key that seems to work (i.e. to move to the next key in the code) is 0. I can also press enter to confirm but it always fails (since the only code I can enter is 0000...0). 

I've also tried pairing from the bluetooth preference and changing the passcode option. However this won't work either. 

Any ideas? The keyboard was paired with another MacBook Pro (I don't have access to it anymore). Is there any method to 'reset' the keyboard to factory settings?
If only one number key is working, it sounds like a hardware issue. My brother had a wireless keyboard that flaked out and only certain keys functioned (although in his case it was from a liquid spill).

Do you have any other Bluetooth-capable device to test with? Any iOS device can pair with the keyboard to test it.