Gunblade, a disk sector is a small piece of information. A lot of disk sectors make up the rest of the information and the sector is the unit of access on the DVD drive of the PS2.

Now you say there's a lot of drive noise. If that's at the same time as your sound distortion, then that occurs because of a sort of data under-run; the next piece of sound doesn't arrive at the right time to maintain continuity.

You might yet have had a problem in your drive (although I doubt it) when you smelt burning. That circuit might be a higher voltage. That's four screws to remove and you could have a look and a smell there.

Finally, are these rented games? If so have a look for scratches and other blemishes. You said that the CDCheck program reported no errors - that's just a guide because it's a different laser etc.

If Dal has the time to play through to the point you suggested (!!!)