Still letter boxing on iPhone 5

I have found a few users with this problem and a few solutions, but none work for me. I have created an app at 640*1136 and included a Default-568h@2x.png image at the same size, yet the app still letterboxes at the top and bottom of the screen as if it was made at 640*960. I tried fiddling with scaling but then that makes the app cut off the bottom on smaller screen sizes. Any solutions?