I had this issue with my CD RW drive for some time now.
I have a Yamaha CRW 3200E-VK and it can't erase TDK 700 MB CD RW discs properly. I would use Nero to erase the CD and the contents of the CD still show up in Win XP explorer when the erase is finished.
I had to use other PC with a Plextor CD-RW drive to erase the CD-RW disc now.
The Yamaha also has problems reading some of CD-RW dics that the Plextor erased.
The Yamaha can still write to CD-RW discs, but I don't know why it can't erase and read erased CD-RW disc properly.
Does it have dust on the lens and another fixable issue?