MY HTPC (Windows 8 64bit) is using a AMD Radion HD 6570 - HDMI direct to new Samsung UN55ES7100 that replaced a UN55C7000WF. Nothing else changed... only the TV. Now HTPC jitters. I can reslove by changing refresh rate to 24 hz. Is this cool? or am I missing something? I have installed the latest AMD drivers for this card and Win8.