Re: 360/NBA 2k8 Question...
The same thing was happening to me. The system would just freeze up and say disc is unreadable clean with a soft cloth. I did a little research and what I do now is first eject the disc tray. Then let the 360 start up without the game. Once you get to the 360 menu screen close the disc tray with the NBA 2K8 disc inside. The system doesn't like when you start up with the game already in there. I believe some sort of memory has to clear out.
By the way, mine did not get scratched.