Hi, I have the same problem and have read loads of comments about solving it.
I've got a Sony DVD RW DW-U18A, remedys included reinstaling drivers (
dosent work), flashing firmware (no need), replace drive or have mended
(drive ok).
Loads of remarks about XP not supporting DVD burning, this may be true but
if your PC came with a drive installed there is also third party software
installed, if you have added a drive you should also have installed the
software that came with it, this is also not the problem.
System Restore will work as long as you go back to the original instalation
and then turn off automatic updates, this is hardly acceptable.
After far to much messing about I've got it down to one of Microsofts
critical updates, problem is which one! Microsoft have a fix ( Imapi.sys
5.1.2600.2505 ) but you have to PAY for it from Tech support. Rather than
potentially damage your system trying things that dont work, email Microsoft
and complain