UPDATE.
I tried a small game and guess what, no problem. Meteors appeared from time to time normally, the date flashed as usual, and no bright white full screen flash. So I went back to my excessive game...and...same thing.
Perhaps the game just needed to get restarted. Perhaps something in the background (behind the screen having to do with Windows) was doing it. I dunno. When I see it again I will try to get a video as I said, but right now the $%^&^! thing has gone back into hiding.
Thanks for your patience, this had been going on for some time (a day or so) before I reported it. Just as quick, gone. Let's hope it was just a ghost of computers of the past, or something.
