It is working fine at the moment. Make sure you use your active private key, when you register. A login failed means our server is working fine, it is something wrong with the key or bitshare blockchain as it is not accepting the key. Sometimes the blockchain is slow and you should try mutiple times, but if it is constantly saying "login failed" then it is the problem of the key. Sometimes keys can get corrupted if your browser clears the history, so please try re-importing if that is the case.