Sorry for the delay. I had a family emergency.
Anyway, to recap, the problem you are experiencing is do to Norton, specifically the firewall as I mentioned earlier. We need to figure out a way for you to add iTunes to the firewall so that you can log onto the store, however you are experiencing some administrative issues is seems. I am currently looking into this problem to see how to work around it, if we can. I just wanted to drop you a note that I haven't given up, I had to leave town with some family issues.
Also, I found this great link with what seems to be your same problem. If you have some time, read through it and see if any of the advice found on this page will fix your problem. The "pros" are 'toonz' and 'b noir' so pay special attention to their advice.
Let me know if you come up with anything that fixes your problem from the link.
Another option would be to post your question on that same Apple forum. If you want to try that here is the link: http://discussions.a...spa?forumID=797
. Maybe they would have a few more ideas or some tricks up their sleeves to get your iTunes store going. If you do that, my advice would be to provide a link to this thread so the experts their can see what you have tried already.
In the mean time, could you let me know specifically what version of Norton you are running. I will try to look into the problems that you are having.