I'm not entirely sure what the problem is, but after reading this thread I talked to our server guy and this is what he said: The primary server has been having problems and has been down for some time now. In the meantime, the secondary server is handling requests, but some people can't seem to reach it. That confirms the posts in this thread. Some are able to get to it, some are not.

I know it might seem to some as though it's been completely dead for a month and we have done nothing about it, and I can see why you'd be upset. If it were me I know I would be upset if a multiplayer server were down for just a couple days without any evidence that anyone cares. We are going to get this fixed. We're actually very eager to get it back up and running since we know there are people who enjoy this feature. It's a high-priority issue and we're working hard on a solution right now.