WS_FTP - Multiple PORT command errors

Question/Problem: To solve the "Retrieve of directory listing failed, PORT command" error, it is suggested that I enable Passive Mode. When I do this, I get a "503 No PORT command issued first" error and to solve this it is suggested that I should disable the passive mode. How do I get out of this repetitive cycle?

Answer/Solution: This is most likely due to an interaction of a local firewall and a remote server that are acting in opposition to one another. If your firewall is set to refuse passive transfers but the remote server requires passive transfers (or the other way around), the only way to get out of the loop is to disable the firewall (for example, Zone Alarm) when connecting to this particular site.