Hi JK,
Can you remind us which version of Norton you are using? If it's 2002, I believe they have now withdrawn support for that version, but they don't think to tell people that when they renew their subscriptions.
The problem, as you rightly say, is that without those vital Live Updates, you could be leaving yourself vulnerable. On the other side of the coin, if you are not doing the Live Updates, how would you know if there is now a fix to your problem?
As I have suggested before, the subscriptions are for the Anti Virus definitions, yes? So, as the problem seems to be with the Firewall why not keep NAV, and just change the Firewall for something else, such as Sygate?