I'm not wanting to change AV's though.
Personally I wouldn't touch Norton with a 10 foot pole.
I used to work for an ISP, and easily 20% of all support calls coming in were the direct result of Norton screwing things up. (timing out while downloading email, freezing the PC, etc.)
Switching to a different anti-virus program (ANY anti-virus program) was an instant fix in pretty much all cases. Norton used to be pretty decent, but has been going downhill rapidly for quite a few years now :-?