Kim O'Hara wrote::coffee:
You may be able to resurrect your keyboard by popping the affected key/s off and giving it a clean-up. I know you could do that with the old ones but the new ones like http://store.apple.com/au/product/MB110LL/B/apple-keyboard-with-numeric-keypad-english-usa?mco=MTA4Mzc4ODA# apparently can't be disassembled.
HOWEVER, you could try washing it - as per http://forums.macrumors.com/archive/index.php/t-1012230.html.
At your own risk, of course.