Does your LAN also require you to web browse through a proxy?
Port 80 is now important because of the new gwebcache system and Gnucleus (you are using a clone) since it needs to access a web page (outgoing connection) at a outside web site to get started for the first time out.
Try this link to get more info
http://www.zero-g.net/gwebcache/
And download a more advanced, improved and spamware free version here
http://www.gnucleus.net/