851s will not burn CDR or CDRW

I have an 851s that will no longer burn any type of CDs. It first stopped burning cdrws and now it no longer burns CDRs. It still does an excellent job of burning DVDs.

I borrowed a friends 851s and did some comparison testing.

His has no problem burning CD media, but mine does a better job of burning DVDs according to Kprobe and Nero CD-DVD Speed.

My question is should I RMA the drive? I just don’t want to end up with a replacement that might not be as good on DVD media.

Will the drive deteriorate to the point where it no longer can burn DVD media either? Or are CD and DVD writing unrelated?