NEC DVD_RW ND-2510A (Burning problem )

My NEC won't allow me to burn films which I have downloaded from the NET.I use NERO 7 Premium to convert and burn --but it just spits out the disc.I've tried using different makes  of disks-No difference.I printed out the error report, and it says "Error reading fault".

My computer plays films downloaded form the net.

The CD/DVD (NEC ) plays music cd's

It just refuses to burn any of the films I have downloaded from the NET.

Computer specs:

Fujitsu siemens 3.2gigb

1 gigb Ram

Windows xp service pack2

200 Gigb HD

I would be very grateful if you could help with this prob.

Arthur Short