MOVIE MAKER VERSION BUILD 16.4.3522.0110  APPLE Imac 24 ,by bootcamp installing WINDOWS 7 HOME PREMIUM.

BLACK OUT WITH FLICKERING PORTION LASTING FOR 1 SEC AT BEGINNING OF PLAYBACK OF EDITED VIDEO. LOADING *MP4 OR *.MOV VIDEO CLIP IN MOVIE MAKER, EVEN WITHOUT EDITED, SAVED AS  *.MP4 FILE. THE SAVED FILE ALWAYS HAS THE ABOVE NUISANCE PORTION AT THE BEGINNING OF PLAYBACK.

UNINSTALLED MOVIE MAKER THEN RE-INSTALLED,FOR SEVERAL ATTEMPT, THE PROBLEM STILL EXISTED.

  IN ANOTHER COMPUTER,SAME WINDOWS 7 VERSION,SAME MOVIE MAKER VERSION, NO SUCH PROBLEM.

Thanks for expert advice.