Well, it worked great for a week, then the BSODs began appearing again. Eventually the hard reboots corrupted WindowsXP to the point where it would not fully reboot, it would just stick at the XP welcome screen. I had to use the Recovery Console and
a lot of tedious typing to get the PC working again.
Now, so far it is working again, no kernal_stack errors after a week... I may get brave and load Norton AV back in and see if the system is unaffected.