To cut a long story short, I reckon it was because your firewall's settings weren't configured properly. Perhaps they were too strict or just not set as they should have been. I've used Norton for a long time, and I've used it with many different operating systems, and I've found it to be of little trouble to me. If you want to install it again I could run through each setting with you and see if I can help

Send me a PM and I'll send you my email address if you want to do that. I use Norton Internet Security 2005, but the settings will be more or less the same hehehe. If you can't be arsed with all that, maybe you could try ZoneAlarm or something instead

I used that for a while and it was pretty good, but my home network suffered a little because of it. I had to mess around with it for a while to get it set up right. If you want to use that you can get it here:
www.zonelabs.com they have a free version and a commercial version. For general purposes you won't need to pay for the commercial version, the free one will suffice