Hotmail's Annoying Upgrade Your Browser Message.

Any body else is getting following "Upgrade your web browser" message on hotmail? I some time get following "Upgrade your web browser" message on Windows Live Hotmail web site. BTW I always use latest version of Firefox.

I can live with that annoying message but couple of time I got that screen while I was sending the message and I lost my composed message because there is no continue button or link which can take you back to what you were doing.