I have Messenger sign in automatically when I turn on our console.
We use the messenger feature quite a bit with Video Kinect.
Recently (in the last couple of months) every time we start up our console, after exactally 10 minutes we get the "disconected from messenger" alert.
It happens EVERY TIME, exactally 10 minutes after the console is started.
Xbox live stays connected, and any there doesnt seem to be any interuptions in service. Many times we are watching netflix when this happens, and there isnt even a hiccup in the video. The xbox 360 is hard wired, not wireless, and our internet connection is reliable.