I dumped Thousand Arms (U) yesterday and it appears to have a form of copy protection I haven't seen before. The disc is perfect, but EAC was reporting all errors on the audio track. With "Read C2" turned off the track dumped 100% quality.

I dob't know i this was used on any other games, but it might be something to check if you run accross a seemingly perfect disc with undumpable audio tracks.

Hmm, there is at least one more similar case - Sharks! CD32, it's a homebrew/unofficial game, which was sold on CD-Rs, contains thousands of errors on CDDA tracks due to incorrect mastering/burning (dunno, whether it was made intentional or not).

Are you sure it's copy protection? Not every copying program uses C2 error correction after all and I doubt that even the PSX reads that data. Have you tried burning your dump and testing it on the original hardware?

It may not be copy protection. It may be that the disc was simply mastered in a non-standard way resulting in false c2 errors. In any case I'd guess it would only effect the audio track extraction. I'd agree the psx probably doesn't use c2 judging from its poor fault tollerence. I'll burn a copy and make sure though.