To verify that your port is not blocked, telnet to router4.limewire.com:6346. I used MacSSH to do this but any telnet client will do. The 6346 as the port number is necessary for this test to work. If you get a "GNUTELLA OK" in a window then the connection is fine so LimeWire is installed improperly or missing components. If you get a connection failure or similar then the port that Gnutella uses is blocked (or in rare cases the server is busy).