Compatibility problem: samsung r780 only reads some cds

I have a Samsung R780, running Windows 7 64-bit. It has the supplied dvd drive TSST TS-L633C. I can play dvds properly; I can burn cds properly; and I can play (and rip) many audio cds properly. But some audio cds cannot be played properly. They play only with massive distortion, and the media player finds no track information for them.
I first thought the problem was with these particular cds, although they are all almost new (purchased no more than 6 months ago) and have no obvious damage. However, these cds play perfectly on several other drives (for instance the TEAC DV-W28S-R91 on the other Samsung R710 we have - also running 6-bit 7 - and on a TSST TS-H353B on a Dell desktop running 64-bit XP). So the problem is not with these particular cds.
I have tried several media players (for instance, Windows Media Player and VLC), but the problem is the same in them all. So the problem is not with media player.
Samsung initially thought that the problem was in the particular drive, and they have just replaced it with an identical model drive that they have tested and say is perfect. But the problem is still there - some cds play perfectly, but others only play with massive distortion.
So if the problem is not with the drive, and it is not with the cds, and it is not with the media player, and it is not with Win 7, then where is it?

And the problem is SAMSUNG !

Yes, Samsung Germany have just told me that the problem is that some of the CD/DVD drives they build into their machines are inherently incapable of reading some cds (and dvds), whereas other drives they use can. So far, so good, but then comes the really customer-friendly bit ---- they don't know which drives will do what (or at least they won't tell me) and they leave it to the customer to find out. Naturally, when the customer does identify a drive that is inherently incapable of working, he/she is responsible for replacing it - and thereby voiding the guarantee (clever, that bit, isn't it?). Samsung are only prepared to replace an inherently non-working drive with another identical non-working drive.

What more can I say? Good customer service looks different to me. The only sure recommendation is "If you want to be safe, never buy Samsung"