I am getting "black screens" that flash and then go back to correct display, every few minutes or so: very frustrating.

I have tried a variety of fixes, but can't seem to find a way- I am not sure this is DF, but worth a try?

Thank you for your help resolving this!

(Win7x64, 2 30" monitors + 1 small displaylink monitor)

The easiest way to find out if it is DF is to shut it down and then see if the screen flashes stop or not.