watching recorded program problem

When we are watching a recorded show on our DirecTV recorder, it will suddenly which to a blank screen with "unknown" in the lower left-hand-side of the screen.  I found that I can click 'prev' button once to go to the previous screen and then click 'prev' again to take me to the recorded show that I was watching and it continues without missing anything.  This only occurs when watching recorded shows and not regularly.  I have reset it multiple times and it still does it.  I think it is something in the 'genie' unit but it does not do it all the time but is getting more frequent.  It is a 'pain' to deal with.