My computer was in sleep mode, with the lid down. I opened the lid and got it out of sleep. There was a white screen with a transparent file folder with a black question mark in the middle of it. I shut it down, and turned it back on. It made the start up noise, but all that happened was a white screen. I did this a few more times, and the same thing happened. It was fully charged and everything. Also, the computer is the last 13in model with normal osx (not leopard). My computer is turned off now, and i dont know what to do. I dont even know what that folder means. Any help is appreciated.