Macbook's screen stretched out?

My husband left his macbook's cover open, two year old pressed some keys, now the screen is all stretched out, not centered, and detecting native display and changing options in display tab is not solving the problem. At 1280x800 I still have to bring curser all the way to the right in order to access the unseen part of the screen. Help save my silly husband a trip to the mac store? We have no extra displays connected and I've disabled all hard drives and other external devices.