Jonny,
Just sent you a copy of my servers.dat file. At least now you should be able to get into the lobbies....BUT you're going to need a lot of luck (and patience) when playing multiplayer. To put it simply, multiplayer is broke and has never worked properly. You should have no problems at the beginning of the game, but as the game progresses, the hick-ups, bugs, resyncs get worse. You will soon loose interest in it...but, Good Luck anyways!