Can't connect...

I downloaded a qtella, gnewtellium and napshare, tried them all and none could connect, :-(. So I know something about those firewall issues, ran telnet connect1.gnutellanet.com 6346 and got a connection. No simple packet filtering firewall here, it seems to me... So I tried the handshaking I found in the protocol, but I could be doing a lot of things wrong, here:
GNUTELLA CONNECT/0.4
followed by a newline to end the sentence and another newline, and the connection closes immediately. Somehow, I got the feeling that all three of my clients get exactly the same response, since they are very fast in reporting an error, except NapShare (IIRC) which times out, but maybe after several tries. What is going on here?
Anyone who can help me out?

Thanks, David