Please see the following thread as it might provide some insight into your problems.
http://www.gnutellaforums.com/showth...threadid=17321
Pay special attention about where your connecting from i.e. work or school. Also please be aware that some smaller ISPs have began disabling p2p use on their networks.
You should contact your ISP to verify that this is not the case --it will save everyone a lot of time helping you if you have checked these things first.
Hope this helps.