Some folk try to exceed the 60Hz rate. You did change the pixel sizes but I see no mention of rate adjustments. Remember that there is NO STANDARD for setting that. ATI does it with their control panel, Nvidia another method and so why didn't you go in there and force the rates to what your display will do?
I'm running Win7 x64 with 5GB RAM. I have the Planar PXL2430MW monitor and it flashes on and off in a somewhat random fashion. I just reduced the resolution from 1920x1080 to 1776x1000 and it seems to have corrected the problem. The picture is obviously smaller with black borders and my question is how I correct this so I have the picture size back.