Out of 56 channels we have running (spread over a number of machines) we probably have one or two drop spontaneously every week, roughly.  These are not restarted automatically, when they die they stay dead.  The window for that channel will still be present when I look in on the server, but the channel corresponding to that window in the Foxweb Channel Status window will not be present.  When this happens, the channel never restarts.  If I manually close the dead window, the channel does restart.