Firefox login problems

Hi.
I recently have problems with loging into hotmail from my.msn.com. I have
the Hotmail inbox column on it. After clicking an e-mail message i get:
"The Windows Live Network is unavailable from this site for one of the
following reasons:

* This site may be experiencing a problem
* The site may not be a member of the Windows Live Network

You can:

* You can sign in or sign up at other sites on the Windows Live Network,
or try again later at this site."

I'm using Mozilla Firefox. I have never had this problem before.
Although i tried with Internet Explorer, and it's working fine...

I did get answer to delete my cookies. It helped on the beggining, but the
problem is back (even after deletingcookies and temp.)
Any other suggetions?

Thanks