I have the same problem, although if i back out of it and then back in, usually it will connect me to a match, so nothing major here that i can't deal with. But i believe it has something to do with my bad wireless connection, because it has trouble connecting to the server very frequently, often having to wait tens of minutes sometimes waiting for my wireless connection to be stable enough for the game to save to the server. So that might be the problem if you are on a wireless, albeit a bad one, or if your connection period is a bit faulty.
If you are on a wireless connection, try plugging in an ethernet or whichever cable you can connect with and see if that fixes the problem.
