change of port problems

[learner]

I have WIn XP Pro SP1 + updates. I am using Flashfxp v2 build 908 and internet connection sharing and ZoneAlarm Pro. The problem is that my friend has a server and he had it set on port 21. I turned my firewall down to medium setting and everything worked perfect. However he had to change the port and now uses port 30. With my firewall turned to medium as before and my settings changed to port 30 I cannot connect. I get the message DATA CONNECTION ERROR 10060. He has other people connecting on port 30 so neither my friend or I can work out what is wrong. Any help on this problem is much appreciated

Thanks