Yes, I am referring to commercial CDs. Nearly all are classical, many I check out from my county library to play while I'm working. Of the last few that gave me trouble, one was an EMI that said it was DRMed, but I discounted this being the problem because it played perfectly well up to track 7 before it failed. Most don't say anything about DRM that is obvious. Its usually the later tracks somewhere that they fail. I figured if it was a DRM problem it wouldn't play at all.
I figured it was because they had scuffs on were too bad for the error correction. Which is why I'm trying to figure out why they generally play on what are probably the lowest quality drives (car cd player) but not the highest (Plextor).
I'm running some flavor of Linux on nearly all the computers.