My game keeps freezing! I need Help!

[ToXXiiC]

Hello, I have the tomb raider triology and it has legend and anniversary and underworld. But when i play anniversary it always freezes like while im playing. And there is no scratches wat so ever on the disc. But when i play legend or underworld, nothing happens, it completly fine but its only when i play anniversary is when it freezes. And i have played other games like mw3 and wwe'12 And that doesnt skip or freeze. Anyone know what to do? Oh and its the ps3 version