Hmm, no virtual drive or emulation software at all? I don't have any experience with Ideal DVD Copy, so no idea if that could be the culprit or not.
Nero's InCD component, if installed, can make things a bit squiffy.
I've got DVDFab installed myself, and have no issues, so doubt that could be a problem.
Try downloading ImgBurn, and slip a blank Verbie in the drive - does ImgBurn say the disc's not blank?
Have you tried the same discs in another drive - say, on a friend's PC? If so, do they burn correctly?