In addition, here is the relevant debug lines when i do a DCC file send (which also does not work)
-> irc.secsup.org NOTICE Fatal_4 : DCC Send 2003-02-18_15-14_abc.rar (203.217.64.102)
-> irc.secsup.org PRIVMSG Fatal_4 : DCC SEND 2003-02-18_15-14_abc.rar 3420012646 3501 34855
You can see that it is using port 3501 for that request.
