Core FTP IE6 Client Connection Problem

[proliant-800]

Configuration Details
I have just installed and configured Core FTP Server (1.0 build 215).
This server operates behind a firewall on a private IP address scheme, (192.168.xxx.yyy). The router has been configured with a Port Range Forward of 10 ports to the servers IP.
The PASV port range has also been set within Core FTP. I only require 2 concurrent connections.
The FTP server has also been set to a non standard inbound FTP port, because the ISP blocks port 21.

Client Side Network Details
The remote client uses IE6 to connect to the FTP server using the non standard port. Although the initial logon appears to be successful, the client connection times out. However when I try this from a client on the same LAN as the FTP server, I can access the FTP site. I have also checked to ensured that all IE6 client’s have the setting “Enable folder view for FTP sites” set to has been disabled and that the “Use Passive FTP” setting has been enabled. I also use ZoneAlarm, but it has been switched off.

Server Side Log
[20071107 16:53:02] 3 domain(s) allowed...
[#1] [20071107 16:53:02] Starting domain - My FTP Site (#1)...
[#1] [20071107 16:53:02] My FTP Site active...
[#1] [20071107 16:53:17] [82.91.xxx.yyy] connected
[#1] [20071107 16:53:17] [anonymous] USER anonymous success
[#1] [20071107 16:53:17] [82.91.xxx.yyy] anonymous disconnected
[#1] [20071107 16:53:39] [82.91.xxx.yyy] connected
[#1] [20071107 16:53:39] [allusers] USER allusers success
[#1] [20071107 16:53:39] [allusers] PASS ********* success
[#1] [20071107 16:53:39] [allusers] opts utf8 on failed
[#1] [20071107 16:53:39] [allusers] syst success
[#1] [20071107 16:53:39] [allusers] site help failed
[#1] [20071107 16:53:39] [allusers] PWD success
[#1] [20071107 16:53:40] [82.91.xxx.yyy] connected
[#1] [20071107 16:53:40] [allusers] USER allusers success
[#1] [20071107 16:53:40] [allusers] PASS ********* success
[#1] [20071107 16:53:40] [allusers] opts utf8 on failed
[#1] [20071107 16:53:40] [allusers] syst success
[#1] [20071107 16:53:40] [allusers] site help failed
[#1] [20071107 16:53:40] [allusers] PWD success
[#1] [20071107 16:53:40] [allusers] TYPE A success
[#1] [20071107 16:53:41] [allusers] PASV success

Client Error Message
An error occurred opening that folder on the FTP server. Make sure you have permission to access that folder.

Details:
The operation timed out.

I have used this configuration with other FTP server programs without issue. Any help on this would be very much appreciated.

[proliant-800]

Thank you for the information.

I have just tried to connect to ftp://ftp.coreftp.com. Whenn I attempt it I get the message...

Internet Explorer cannot display the webpage.

I dont believe I am using a proxy server at my location. I know DNS is resolving ok and that my firewall has been setup correctly, as I have just installed another FTP program for testing and using the same setup, a remote IE6 FTP client can connect without issue.

How can I switch on the port logging within Core FTP server?

Many thanks...