I know my client (in that example) is connecting via normal FTP, not SSL. I went out of my way to demonstrate that fact to you by showing you that my client was not built against any SSL libraries. The problem is that even though I am connecting with regular FTP, Wing is attempting to encrypt data to my client - which is when it hangs. Our firewall is not able to inspect (and translate) the CMD channel messages from the server because they are encrypted.
My client should see something like:
227 Entering Passive Mode (192,168,0,1,252,70) if the passive external ip address is not properly configured, or
227 Entering Passive Mode (An.External.Ip.Here,252,70) if it is.
My client receives neither, it receives an encrypted response from the server at that point. Our firewall will automatically translate our internal IP to our external IP when it passes through, but it can't do it in this instance because it's encrypted (and my client is unable to communicate via SSL.) We need the CMD channel to go out unencrypted, and encrypting the DATA (in a secure connection) at that point is fine.
I can configure vsftpd to have an identical configuration (passive address, ports, etc) and it works because those CMD channel messages are not encrypted.