When an account is disabled, make it clearer to them that this is the problem.
If the user is already logged in, and they take an action, such as leaving a machine comment, there is no feedback about a problem. The comment isn't posted, but there's no error. The server returns Completed 401 Unauthorized
If the user logs out and back in, they can't log in. The login error says "There were errors trying to process your submission". The server returns Completed 200 OK