It soulds like both computers are trying to use the same client port. Follow the directions here >>
How can I play through a Firewall?EDIT: The link did not scroll down to the right part like i hoped it would, So here is a quote of the part you are looking for.
If you have multiple computers behind a firewall and you want to play multiplayer with 2 or more of them at the same time, you must ensure the Client Port setting for each computer is set to a different value. You will find this entry in the file nwnplayer.ini Simply double click on it to open it, and look for the Client Port= line in the [Profile] section. Change this from the default value of 5120 on each machine. You have to stay in a certain range, so use numbers like 5121, 5122, 5123, etc.
Modifié par Lightfoot8, 30 janvier 2011 - 08:53 .