I have a similar problem. Until about 3 days ago, people could see my server, play on it, and everything was fine. However, a couple days ago, my server stopped appearing on the list. So I just gave my friends the IP like usual, and it didnt work... it worked for me, but not for them. I made sure the firewall was down and all, then I found out my IP had changed (??). I looked in the Network/Internet connections properties, and sure enough, it was different from 3 days ago. So i gave my friends the new one, and they still can't connect or see it on the list. I made sure dplogin.com was set as the master, and all my settings are the same as when it used to work. So, what could be wrong with it? Any help would be greatly appreciated, because until this comes back on the list, my clan is at a standstill.
-Steeb