Can't use p2p programs with my 6211-I2 (by 4 users)

Make sure there is no firewall running. Even the windows xp firewall can screw up p2p applications.

Try this. It's what helped me as turning the firewall off in the modem never helped. Set up the DMZ for the computer (or other router, such as WIFI) that you will be using torrents on. Using Utorrent, you can easily test if the port is running open or closed. Port forwarding and firewall settings never got me anywhere. Let me know if you need more help or if this worked. :)
-Tim