This article is from the CD-Recordable FAQ, by Andy McFadden (firstname.lastname@example.org) with numerous contributions by others.
There appear to be three kinds of DVD players:
1. Those that can play CD-Rs.
2. Those that can't play CD-Rs.
3. Those that damage the discs.
Kind #2 is the most common. Kind #3 comes with a warning in the manual
(you do read product manuals, right?) that tells you not to play CD-R discs.
It is possible that some players in category #2 are actually in #3 and
just aren't labeled as such, and it may be the case that players in #3
will only damage CD-Rs with specific formulations.
If playing CD-R discs in your DVD player is important, make sure the
player can handle them before you buy a player. See section (2-13).
It's a little unclear what the player is doing to damage the CD-R media.
The playback laser would have to be operated at a wavelength and intensity
that caused a change in the recording dye layer.
There are no known instances of DVD-ROM drives that damage discs.