Are you referring to Live Mesh Beta? If so, see:
http://social.microsoft.com/Forums/en-US/LiveMesh/thread/17f3180b-2960-4cee-be25-8db53363c0ea
It will cease working within about 2 weeks. You must remove Live Mesh beta and use Windows Live Mesh, which is the new version. It will not work on XP, but will work on Vista and Windows 7.
Once you've done this, if the problem persists, post your issue here:
http://windowslivehelp.com/forums.aspx?productid=24
-steve
~ Microsoft MVP Windows Live ~ Windows Live OneCare| Live Mesh|MS Security Essentials Forums Moderator ~