Are you building to the phone or doing it in the editor? If editor, then make sure your window is big enough to contain the full resolution - see the "stats" button on the game window to see the real size there.
Otherwise, check the Maximum height on UIRoot - it should be more that 1024. In an older version, if you exceeded the max size, it defaulted to potato - so nothing made sense. If you're using the free version, you might be so lucky.