To give you an update of things, due to a problem with the VGA driver, I had to format my HDD -about time too, with XP this is my first format in 2 years, whereas before it was every 3 months- and re-install everything,
Nero included. I had the exact same problem (with Nero 6.3.1.6) and I manage to solve it by downloading the DVD plug-in. Strange thing is, it's supposed to be included. Anyway, no problems now.