Hi I have the same problem.
I have XP SP3 on a DELL D600 laptop.
I think that this is due to a Windows or Zone Alarm update or a virus.
I use Windows Defender. I did a full scan and nothing has been found - which leads me to think that it is an update problem.
I use Nero 6 to copy non-protected DVDs. I have never had a problem until last week.
Initially I thoought that it was due to loading an old DVD editing sofware - but I have removed this and I still get the same problem - copying stops between 90-98%.
The program does work if I reboot the machine.
Also I have CyberLink Director 4 installed and that has started to malfunction with a C++ runtime error.
The old software did install .NET 2 but I have now removed this and still get the problem - Director will not run.
My machine has been doing funny things like not loading a web page. I have Zone Alarm Firewall and I think that this was updated recently also.
Hopefully I have a previous version of ZA and a Restore point before the updates, which I will try.
If anyone knows why this is happenong then an answer would be greatly appreaciated.