Ok...I think I got it. Two of us were IG with no problems. I think what was happening was when the program is running and the file is open, it resets. When we look at file, it is good to go but once we close it, it resets. The next person would log in and at that time, both ports would be the same.
Solution: Program not running when changing the file. Change the ports, save and exit. Then log in. If any part of the program is running and the nwnplayer.ini file is opened, it will reset to 5120 or 5122. Right now one is set at 5118 and the other at 5123.