Yesterday I took delivery of a 13" i7/16GB/512GB SSD. When I connect it via DisplayPort to my Dell U2713H display, I get significant stuttering of the mouse pointer when using my Magic Mouse. (Dragging windows is extremely choppy too.) I did notice that closing the lid would sometimes help, but manually invoking a sleep and wakening again would rectify the stuttering. I've ran Apple's diagnostics, but no issues came back. Is this the same as the known freezing issue or is it a different problem? I have an appointment at the Apple Store on Saturday morning.