Messenger 8.1 is currently under going a private beta – this is to help us find and fix bugs\problems with the up coming release before we release it to the world.
Please don’t install builds if you are not part of the Beta.
Please don’t install builds that are not from Microsoft.
Please do sign up here if you want to be a Microsoft beta tester in the future: 

If you have a comment/question/concern/discussion topic/rant/rave/other – please head over to the Windows Live Messenger Newsgroup.