Kipendale wrote on Nov 22^nd, 2015 at 11:38pm:

I don't actually understand why it works, but all i did was shut down my computer, restart and it all works just fine; cabin ticked on and no flickering now!  8-)

All I ever have/had to do to stop the flickering, was to reload the 707 into FSX. That was it until the next time I loaded it. Now that I have a 4GB GTX 770 OC, it rarely, if ever, flickers. :-/

EDIT. Once I upgraded to the i7 3370k, 32GB RAM, and the 4G GTX 770 OC, it rarely, if ever flickered. So I think that the more powerful the computer, the less likely it is to flicker.