Right, so I'll try to help you (I haven't personally looked at the game client much, so I do not know how it connects, and so but I'll try and help you to the best of my ability).
First of all, could you do a netstat -noa in CMD (Start -> Run -> "cmd" without the quotations ("") and then execute the following command):
I suggest, that you close all external, background applications that may use external ports especially other
active FTP mirrors. You should get a brief list of IP addresses, and a few ports. I want you to post that list in here, and I'll troubleshoot your issue further. You can mark/copy the list by Right Clicking, and then choosing the first option available (Mark) and mark all the lines as per request, and then right click once (which will automatically copy all the lines, then paste it in this thread).
- Meti