My adapter is on the way (Apple MiniDP adapter) but I have read many compaints about that adapter and this same issue. It seemed to have been resolved by pluging the USB cord into a powered USB hub or separate USB port on the motherboard (where the adapters USB cord is the only one) as the adapter takes the entire 5v to operate. I know this was mention earlier in this thread but didnt seem to get much of a follow thru. Any experience with this fix?
I have my Apple adapter plugged into a separate USB power adapter (a spare iPhone charger I had lying around) and it worked great at first except for the very rare screen blinking on and off.
Then I swapped DVI cables with the two other monitors. That seemed to have fixed everything. Two hour gaming session last night went without a single hiccup. No snow, no video noise, no blinking.
Of the three LCDs, my left most monitor is running off the Apple adapter. I swapped the center and right monitor cables to cure the remaining issue.