the last 2 days my 3gs has been locking up on the main screen where I enter my passcode. I tried several times to had boot it, but it keeps happening. I noticed that the Power button is off balanced as if it was pressed too hard and now its stuck.... I even tried to take off the passcode entirely, but when I when I go to Settings, passcode lock, the iPhone freezes again. I have had the 3GS since 3/2011, can I take it to an Apple store to exchange it since it's under 1 year? any help is appreciated.