Have had a look at my own settings for OE, within Norton 2005 and by going to "Firewall" and then "Configure" and "Programs"my settings read as Automatic and Multiple.
Background Noise made a very good point a little earlier, by removing references to OE and letting Norton rewrite the rules when you next start it. This might be worth a try as well.
Just thinking about this a little - have you or anybody else done anything at all to the router of late?
Conan