Lets clear some things up, the only time a scratched disc can damage a drive is if the scratch is really deep. When u insert such a disc it may actually begin to bounce as the drive tries to access that area and this can damage the lense (I've had it happen) - generally though, this is rare and u wud know it was happening by the strange noises your drive wud make (clatters, whines etc.) - even then it wud only damage if it was left for some time.
if u haven't had these symptoms then I wud guess that its just that u cannot access certain parts of it.
so it probably is not your drive.
Now Samsung have had a bad rap bout their optical drives but this only applied to their early (1st?) generation drives, their current range, specially the one in the box, performs brilliantly with cdr/w's - I had a scratched audio disc that refused to read past the 2nd track but it didn't hurt the drive cos I removed it asap - so I really doubt if your drive is damaged.
the definite test wud be to play some other game and see if it freezes!