Not sure, but it is most likely the media.

Subject: Not sure, but it is most likely the media.
Name: SickOfItAll
Date: 2/9/2001 3:54:18 PM (GMT-7)
IP Address: 208.1.79.30
In Reply to: help: wildly inconsistent cd-r diagnostic results posted by Dude
Message:

I've never had much luck with the non namebrand discs. I've also never had a problem with TDK brand discs, both RW and CD-R. You really do get what you pay for