I have a similar issue.
I've tried everything posted ont he first 2 pages (i haven't looked at the 3rd yet, i was expecting it to be a list of thanks) and nothing has worked.
I have exactly the same symptoms as everyone else, it's only the one account that won't log in on Live, any other account will login on Live, i can log in with the account on default messenger, i can check emails and everything, jsut not log in while using Live.
The one difference between my problem and those described by others is that, mine comes up with the error after about 5 seconds (the average amount of time taken to log in on any other account) and the "Hobojangles is now online" tihng pops up on other peoples PC's a few seconds after it errors. When troubleshooting it's all ticks, but it still doesnt work, the methods described by Victoria that work for everyone don;t work for me.
This sucks
