You can try a reset. HOld down the sleep and home keys, past when you see the red power down slider and until you see the silver apple. Let it reboot and see if it fixes it. But even if it does I'd still make an appointment at your local apple store and have them check it out, get the issue on the record in case it happens again.
And if resetting doesn't help then still go to the apple store. What's wrong is likely something for the pros.