A few have mentioned that while running Zone Alarm PRO, they can connect, but get a Socket error. I have run into the same problem [enabled incoming TCP port 21, and outbound TCP port 20], but found one way around it. I found that if I add the client's IP address into the Local Zone, I can then get in and download by typing the ftp details into the URL address of IE, for example ftp://betanet:betanet@216.1.11.166:27015 (sample only - not a real address).

While I found this method of using a browser for FTP to work, I still get a Socket error if I use an FTP client like CuteFTP Pro. Of course, getting people to connect with a brower means that you would have to know their IP address and add that address to Zone Alarm's Local Zone settings.

If someone has found a way to resolve the socket error using an FTP client, would love to hear it. Thank you.