Ok, so as a few of you may know, I have now have a dual display set-up with my macbook. But the problem is, is that it is impossible to line the screens up perfectly, as the top screen (the additional screen) always appears less wide than the screen below (the macbook screen), as shown here: It gives you an 'arrangement' option in system preferences, which does let me stretch the size of the screen to an equal width, but it never actually changes anything. Has anyone ever had the same problem? Or know how to fix this? Not a huge thing but help would be much appreciated.