Try a different connection & listening port to your friend. Good ones to try are between 49152 - 65535 such as 64049. You can change them via Tools > Options > Advanced > Firewalls.

Other than that, I'd highly recommend http://www.gnutellaforums.com/connec...t-connect.html even if you've tried them before. You will have a much better chance of connecting if you persist with these ideas.