Curiouser and curiouser.
OK, here's a thought. I'm guessing that you are accessing your Hotmail inbox via www.hotmail.com or Windows Live, right?
If so, can you try accessing it through Windows Live Mail, please.
http://www.windowslive.co.uk/essentials/mail
Or, depending on your version of Windows, another email client e.g. Outlook, Outlook Express, Thunderbird etc.
These are all desktop applications and, as such, should not be subject to any JavaScript injection. Clearly, it won't solve the actual problem with web mail, but it might at least allow you to continue to manage your mailbox...