Using a AMD Radeon HD 6770 (AMD 633897-ZH1)
Win 7 HP x64
When I plug in a second monitor I get really bad flickering on the second monitor whenever anything video related (Youtube, movie, video games) moves on the primary monitor. I know its not the monitor since the issue only happens on which ever monitor is labeled as the secondary monitor. Everything works fine in a single monitor set up, and everything fine when there's no motion on the primary monitor.
The two monitors are a HP w2007 using a DVI->DVI connection and a HP x20LED using a VGA-DVI connection with a VGA to DVI adapter.