Don't auto level :) That seems to be the problem. Do the leveling yourself. I have been adjusting photos for years and I really don't like what auto level does. All it does is basically push the picture so there is a white spot and a dark spot but it doesn't really look at the picture. What you can do is this. Open levels, there is three little triangles, one black, one white and one gray, drag the gray one over so it almost touches the white one. The white one is the white point, the dark one is the black point, gray is middle. When you drag it over you can se how much white you have, you can then take the white one and push it to the middle to actually get a white spot (or just to lighten it), do the same with the dark and then take the gray one back to the middle at 1.0 and then lighten it if you need to but look at it on the screen and you decide rather than the auto level.