Please do this test for me: Download and install Google Earth Start Google Earth and enter an area and hit go. Then when it stops zooming in... Drag the window around your desktop Does it stutter/stagger in a jerky-like movement or is it completely smooth? Please let us know which Graphics Card you have too. I've just tried this at the Apple store and it was a jerky movement - it had a NVIDIA GeForce GT 120 in it. I'm thinking maybe they're running old drivers - hence interested in what yours runs like.