Since the others are working I would try and force TB to request your password again. a) change your username and try to get mail. When the popup asks for your password, just cancel b) change to your correct username and try get messages again. Now when it asks for your password enter the good one (remember to let it save it for you) and - I hope you are synced again. On the off chance that you are not getting a password request - review your connection details (server name, port number) and verify they are the same as with other accounts that are working. Hope this helps!