Hi everyone Recently purchased a base model Mac Pro 4,1 for a steal. When I try and watch YouTube full screen it the video remains the same size with the rest of the screen black until I click pause, and then the video goes full screen. I have the original GT 120 installed, and as of recently a non Mac 5770. I have pulled the gt 120 and reinstalled with no effect. Anyone have any idea what can be causing this behaviour? Attached is a random video I clicked on to demonstrate the effect.