After reading the access log of mr. THEFORCE, I noticed two peculiar behaviors.
1) Your web client accesses the TASVideos RSS file every hour. 24 times in a day, that is ― with an obsolete URL. You use
http://tasvideos.org/movies.rss . That's ok though, it just creates twice redundant access due to the redirection to new URL.
2) All your access has been with a Referrer field of "-" and an User-agent field of "-".
Normally, the Referrer field says the URL where you clicked the link that lead to that page, the User-agent says which software you're actually using for browsing the site.
Now, this is the problem. User-agent "-" happens to be on my ban list.
But, as you figured out, "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.14) Gecko/20080404 Firefox/2.0.0.14" works just fine when you are using Firefox for Windows.
So it is indeed that Norton Internet "Security" that is to blame in this case.
(That, or my decisions as a webmaster ― but I've been a webmaster for quite a long time and there is quite often some reason behind what I do.)