[igalan]

USB DVD burners don't seem too reliable. My Sony DRU500A (IDE) has burned hundreds of DVDs and it's working as day one (fingers crossed), and it's the same except for the USB enclosure.

I have read about the Roxio icompatibilities. You should try to remove all burning programs and leave Nero alone. No ASPI driver should be installed, and if Roxio or some other installed one, you should remove it. Then with the DVD burner plugged you could try to remove it from the Device Manger and reboot to allow Windows XP to detect it and install driver again.