My "Backspace" key on my 12'' PB suddently doesn't work anymore. It cannot be pressed down anymore. I have to press really hard to have it to respond. My computer is still under 1 year warranty but has past 90 days phone support. Will I be charged $50 for calling AppleCare to have this problem taken care of? How long usually does it take to have it repaired? Do I have to send it in or I can bing it in to an Apple store? Thanks!