[xequence]

You shouldent use any port around 6881 because ISPs tend to block them, as they are often used for P2P.

To test if your ports are forwarded right, take whatever port you use and add it to this URL:

http://www.utorrent.com/testport.php?port=

I recomend using a port in the 50000's.

EDIT: I guess the other link posted does the same thing. I didnt know what NAT was, so I didnt think it was the same thing as port forwarding...