Is my DVD burner beginning to fail?

[mz]

I burn copies of music CDs to take to the office or traveling. This past 
week, I burned half a dozen different titles. Half were bad. Subsequent 
attempts were inconsistently successful, and I discovered some of 
the "good" ones played on only some players. Overall, a number of them 
play on only some players, others don't play at all, and some play some 
of the time. When they don't play, the CD players say there is either 
no disc, "error," or an error w/ the TOC.

The drive is a NEC DVD+RW NC-2100AD. Results are the same regardless of 
the CD-R substrate.

The program I'm using is K3B on openSUSE 11.0 w/ KDE. These are the 
first problems I've run into since switching to GNU/Linux this past 
November. The log doesn't show anything really obvious, which it would 
have to be for me to spot it.

Any ideas as to what to investigate? Or should I just start shopping for 
a new drive?

TIA,
Mark Z.