NOD32 != Norton AntiVirus..... Not related to Symantec at all.
Frodo linked to a blog about the issue happening with Norton as well.
I'm running Norton and seem to be having similar issues. The entire computer freezes and needs a reset after about five minutes of use of the tv server (ie recording or watching). I've configured NAV to ignore the MP folders so we'll see if that helps...
The point also raised in one of the blogs is that this doesn't happen on most PC's which is why they had trouble detecting it.