I bought i7 MB Air 16MB ram for travelling to do occasional Photoshop tasks. It handles 86MB files from a 5D m4 quite well. However, when trying to view files at 100% the image disappears off the viewing area, the image can be viewed at 33% but when zooming in any more only a small corner of the magnified image is visible in the top left of screen. I didn't have this issue with my MBPro. I think I need to change a setting somewhere, any ideas?