I'm not sure if it is corrupted but something is definitely wrong. I'll get straight to the point.
My playstation was on and no one was using it, so I turned it off by simply pressing the Power button on the console. I didn't think anything bad would happen since I always turn it off like that whenever it freezes on me. When it was turned back on (my sister told me this) a message came up saying the PS3 was not shutdown properly and that it did something simailar as if it was updating. Then I took out a game from it (Need For Speed) and put in another game. It was completely fine. But when I put in the game that was in the console when it wasn't "shutdown properly" (Need For Speed: MS) it was as if I had never played the game before. My saved game data gone. Luckily everything associated with my psn account and trophies were completley fine. So what I want to know is, Can the file be restored?? If so how??