After 3 days playing with my new iMac (3,06 GHz. NVidia 130), There is one thing that I can´t find normal. When I drag a window through the screen, it does not flow smoothly, but like "jumping". It is not my first mac, as I have also an Air (1,86 GHz. 128 SSD), and though its screen is not as good as the iMacs, when I do the same dragging, windows flow effortlessly. Are there any settings that I am missing?