Not registering on voip.ms seattle.voip.ms

I am sure I've set my username, password, and server correctly for my voip.ms trunk, but calls in result in a busy signal, and voip.ms reports no registrations for my account. Is there something else I can check? I've created and deleted and check and double-checked the settings so many times, and nothing works.

I know the service works because until a few days ago I used it on my own Asterisk server.