So right now you're using a 2wire?
If you can't figure out how to unblock a port in the router, or port map, then change the port number in your FTP program to port 25, which is the same as outgoing mail. Then have the people that FTP to you connect through port 25. I used to have to do that in my old apartments kuz the complex didn't allow you to FTP, so they blocked out port 21.