Serious Error Message - While Burning DVD w/Pioneer writer

I just bought an External Pioneer DVD writer and it's been working fine until two weeks ago. Now for some strange reason while burning a DVD my computer will suddenly go into a "screen-saver like mode," (my screen saver is actually turned off, as well as hibernation) and I must then log into my administrator account and restart. Someone said it could be that I need to check my power options, to see if my computer is set to shut down after a certain amount of time. But, where do I do that? Could it be a software problem...since it's an external DVD writer? I use Nero for burning DVDs. Or do I need some kind of Windows XP update? Sometimes I get a Serios Error message.

C:\DOCUME~1\KATHYB~1\LOCALS~1\Temp\WER15e6.dir00\Mini030108-01.dmp
C:\DOCUME~1\KATHYB~1\LOCALS~1\Temp\WER15e6.dir00\sysdata.xml

BCCode : 7a BCP1 : C03E12B8 BCP2 : C000000E BCP3 : F84AE384
BCP4 : 03FA8860 OSVer : 5_1_2600 SP : 2_0 Product : 768_1


ANY HELP would be greatly appreciated.