[Lario]

Was gonna suggest ConvertXtoDVD too. Great bit of kit.
You'd use ConvertX if you wanted to maybe drop an avi onto a dvd and make it a "video" dvd. You can actually use ConvertX to throw a number of avi's onto a dvd, create a menu, etc. But that's beside the point. This disc should then be playable on all dvd players.
The other option is to use Nero to just create a "data" dvd. That's literally just using the disc as a storage location, and will only be readable by computers and some dvd players. Actually, most dvd players can now handle avi type stuff.

So I guess if you're making data discs through Nero and the burn is failing, maybe you could try the ConvertX route. If you're making "video" discs through Nero and the burn is failing, maybe you could try the ConvertX route.

You could maybe also reduce your burn speed. Sometimes that does the trick.

Other than that, I'm afraid I'm shit out of ideas.