Perhaps the issue is your connection & security set up.
Have you checked http://www.gnutellaforums.com/host-c...bearshare.html

I just checked my Bearshare 5 Beta versions in Windows 2000, Windows XP & Windows 7 & all connected fine after a few minutes. Two connected with mostly Bearshare hosts, the other with mostly LimeWire & Frostwire hosts.