Has anybody seen the issue described below (three months old BV 7-40, just dealer-upgraded to ver. 5.0 software) :

After playing a DVD for a few minutes, the screen goes blank, but sound continues.  Switching to TV or (P-in-P with TV) and back to DVD "fixes" the problem for another few minutes, until the picture disappears again.

The TV function (connected to Comcast DVR) works just fine (i.e. never blanking of picture).

Does anybody recognize the symptom ?  Help would be very much appreciated.

Best - Matthias