'problem with disc.. may be dirty or scratched'???

[cooterteef]

I keep getting this message. Some games boot right off one time, next time I get this message. I have 2 boxed im trying on one with x2lite, one with cheapmod. I tried on 2 different media types.
Has anyone seen this and why is it doing it and how to fix it?
I dont think its the back-ups b/c they play fine one time..

Thanks!