You are all missing something here.
Point: He has no problems with CDs and rewritable DVDs
Reason: DVD writers have a BIG BUFFER so CDs are no big deal. Now rewritable DVDs write at a much slower speed than regular DVDs. Depending on the brand you have this varies from 2.4x to 8x.
In Nero, just before you hit burn, you will see an option of speed as a dropdown list. It will be marked as automatic. So do the following:
1. Disable your screensaver
2. Disable your antivirus and switch off your broadband router or modem
3. Ramp down the speed to 4x from the dropdown list
4. And burn baby burn
P.S. - if this works for you you might want to consider trying out OpenSuSE 11.0 or Ubuntu 8.04 linux. Unlike windows they
do not need antivirus and do not connect to the internet, update and restart without your permission. With your configuration your system will FLY.