Hey guys.
We've had some trouble getting our host migration working, so for now we're switching to dedicated hosting in version 22744.
That means if you start a game, the game will only exist as long as you are in it. When you leave, everyone gets booted.
I apologize about this, it will probably make it harder to find a game. We hope it will help with stability. We intend this change to be temporary.
for those of you interested, here's what's happening:
Steam occasionally drops players from the lobby we've set up. This wouldn't be so bad, except that steam never tells the player that got dropped. They think they are still in the game. When Steam does this to the host (as seems to have happened multiple times today) it causes significant problems because one of the other players will try to be host, not knowing that everyone is still getting messages from the old host. We're working on this.