Try the fixes in the thread below...they refer to LW but it's the same for FW
Start off by replacing the gnutella.net file...I just downloaded FW after not having it installed for ages & had the no connections thing going on. Replacing the gnutella.net file fixed it right away.
http://www.gnutellaforums.com/connec...t-connect.html

If that doesn't fix things for you, give us your system details & we can try to help more.