Sounds to me like the problem is in the hard drive, Savgurl. I would suggest taking the disc out and start the system up then copy your game saves over to a USB thumb drive (or flash memory card if you have one and a USB card reader). After doing that go into the settings menu of the PS3 to System Settings and re-format the hard drive (you can re-download all PSN purchases as many times as needed so nothing lost there). Once the system restarts and you get your PSN name set up again try the disc again.