As you are most likely aware we are having some issues (503 errors) with our web host and we are planning of moving servers. You shouldn’t receive the 503 errors too frequently at the moment.
We will be moving servers with-in the next few days after I’ve tested the new server to make sure everything works well.
Edit: Everything has been configured on the new server and if you are reading this message you are on the new server. Thanks to mha for providing the new server! Hopefully you should also see some improvement in speed.