Hi, sorry to hear about your gaming problem.
There are really only a few things you can do. First off check to see if the disk is scratched. If you can see scratches in the light, then those aren't too bad as they are just surface scratches. The one you have to look for are the ones you can still see if when there isn't direct light shining on the disk. Those are deep scratches. If you have any of those then you need to either get your disk repaired or just take it back to where you got it from and get it exchanged for another copy.
If the disk is fine and it's STILL happening, then there could just be a little dust on the lens of your console. Just open the tray and blow VERY gently to try to dislodge any dust that might be on there.
Failing that, I don't know what to say.
Maybe when Lyndon sees this, he'll have some other possible answers for you.
Sorry, I couldn't be more helpful.
Jay
Site Squad