Amazon EC2 FTP Client Connection - Error if Passive or Active - No Firewall

I have made a clean EC2 virtual machine running Amazon Linux. All ports are open in the "Security Group" (Amazon's firewall). I connect to an FTP server in the terminal, I can change directories, but I cannot download a file.

• Active download fails with "500 Illegal PORT command; ftp: bind: Address already in use"

• Passive download hangs indefinitely with "150 File status okay; about to open data connection"

• The file exists, I can download it via browser

• I can download the file from an ftp terminal on Windows and Mac machines
• On login the server responds with a message containing my IP. The IP is correct

I don't even know how to begin diagnosing this further. Any ideas would be much appreciated. Thanks