Have you set manualy the Port to: 14147?
And have you disabled your firewall on the Win7 maschine for testing?
You can test it with telnet from the MAC client if its installed.
Edit:
telnet 192.168.1.71 21
Port: 14147 is the Adminport. To connect try the default FTP port:21!
To connect to the admin interface try http://127.0.0.1:14147 and a blank password.
Solution:
The client needs to change the setting
<Item name="Custom PASV IP" type="string">SAME AS OUTWARD FACING SERVER IP</Item>
to the IP of the router doing the NATing.
Explanation:
According to section 4.1.2 in RFC 959, after PASV has been sent:
The response to this command includes the host and port address this server is listening on.
After that, the client may respond with another listing of the IP address and the port it desires to use.
Some clients, such as FileZilla, will verify that the IP address and port given in response are actually reachable. Others will simply assume that they can continue on the same socket where they started. The former is probably more correct, since the protocol does allow for a change of port and address, but it will fail in this case.
Edit
If the FTP server is already using the correct settings, the problem may be in the setup of the NATing router/firewall/etc. It may be altering the data sent through it. The way to identify this would be to do a tcpdump on both sides of the connection to verify that the content of the traffic is the same.
Best Answer
I checked the corresponding Windows service, and it is not pointing to the correct Filezilla server, strange, it is pointing to another Filezilla server which resides in temp directory under users folder.