I was using the system yesterday and the Desktop and lighting must have been exactly right, but I could see noise lines running down the screen. Since that indicates a timing problem, I put it back to 59p Hz and the interference stopped. Perhaps an Windows update was involved, but the screen looks better so I will have to leave it on 59p Hz for a while to see how it goes.
The other strange thing is the Refresh Rate shows as 59p Hz or 60p Hz, which I assume means progressive scan... Since my Nvidia system doesn't show the "p", maybe that is an Intel special designation or perhaps the higher resolution monitor uses it.
Thanks.