Hey I had exactly the same problem like you. I've also postet it int tremulous.net forum but nobody ansewered to me
Anyway, I've found solution for this problem, but i think its not the best...
When I started the server, everybody could connect but it doesent appear in the public list.
So Ive waited and some minutes after the start my server's IP apeared in the
http://tremmaster.quakedev.net/ list, marked as "Timeout".
On this site there's a Port behind my server's IP. When I now use the same port for the server and also configure the firewall, port forwarding, my server is listet in the public list.
I think its a very strange way but now my server's in the list and I wish you, that you can make your server public :wink: