Hi , I´m having a similar problem , i can´t host any module on gamespy , i´ve tried port forwarding too but nothing , i still keep getting that message in a txt log when i run nwnserver :
"GameSpy Server Error: Unable to query the server. You may need to open port 5121 for incoming traffic.[Sun Jan 22 22:02:43] Loading Module: bardo"
It´s terrible because I finally got my friends to play nwn next weekend! Thanks in advance