The brickwall indicates definitely a firewall. As far as I know, Norton 2006 comes with its own firewall. I remember some people the other day having problems with Norton 2005. They solved it by removing all exception for LW in the Norton configuration and then closed Norton. After they reopend it they added LW again and that solved the poblem for them; though I'm not sure whether that will help you.
Have you checked with other people at the student accomm. whether they can use LW and how they have configurated it?
Maybe switching the listening port to a higher number will do the trick. Read here under "Connection Problems" how to do this:
http://www.gnutellaforums.com/showthread.php?t=51361 