Did you go onto the log in page and click on "can't access your account", then click on the option that says you know your password but can't log on? You then get the option to change the password.
It is probably something to do with your ISP not working properly and it may well be that you will have to wait until they correct the problem.
When you type in your user name try putting it in without the @.
It could also be something to do with your anti-virus.