I'm having a strange problm with my ND-6500. It has suddenly decided it doesn't want to burn CDs anymore, at least not all the way through. About 1/5 of the way through the CD it will start grinding, similar to trying to read a bad CD, and finally give up. It seems to be the same spot regardless of what I'm trying to burn. I don't think it's the media as I've been using it for years without a problem.
Also, it will burn DVDs just fine, I just tried.