I've never been able to host a game that my friend could join. He can host and sometimes I will see his game and sometimes it works.. There are times when it will work two or three days in a row..
Mostly tho, he hosts and I just can not see his game. Basically I have given up. There is no rhyme or reason as to why this thing sometimes works and then doesn't. It hasn't worked for months, Every now and then we start it up to see if it will decide to work and one time, a couple of months ago, it did, just after that moon map was added. We played for that entire weekend. Then the next time we tried , a couple of days later, nothing..
We both have win 7 PC's all capable of running this game, our routers are not ones that this game has had problems with in the past. No idea why it sometimes works and other times doesn't. I can see the other servers just fine.
I have tried all the "fixes" including the master file copy n paste idea, forwarded all the ports that people have suggested.. None of it explains why sometimes this game works and I can play it with my friend and other times (most of the time) it just sits there, not seeing his game.