I'm not sure if the title is the most apt description given that when I google the issue the images associated with how i described it. It's a new 2013 Air. 4gb ram, 126ssd. But basically typically when I'm viewing images in preview and close the app, a line of pixels across my screen (horizontally) just freezes. And by that I mean that part of the image stays on the screen, but it's a row of pixels. Images from my google search sometimes showed random white lines, or black lines. Not for more than a few seconds. I can even move my mouse to the line of pixels and it goes back to working 100%. It happens on a daily basis (or near daily anyways) I've had the machine for two weeks. I bought it on Amazon so I may try and see if they'll take it back despite it not being a total lemon. But if there's a quick fix offered here I'd love to try it first. Thanks for any help or suggestions you can offer.