I have Windows Live Mesh installed on a 64 bit Windows Server 2008 system. Whenever I attempt to sign in to it I get an error message saying, "There might be a problem with your internet connection." This happens even though the server has an external connection.
I had this problem on my Windows 7 (x64) laptop, and the problem ended up being that Internet Explorer was in offline mode. Since I never use IE, it took me a while to figure this out. Once I told it to go back online, live mesh connected with no problems.