of what I can tell they probably increased the height of the mainbar (letterbox_bottom) by 5-6 pixels. that transparency you see is caused because of that (as the elements tile the empty area you see at the bottom is basically the second tile of the top of your mainbar).
Try increasing the height a bit and it should be fine.
Guess the team is a bit busy before the launch and they just don't have the time to release new art assets yet. At least I'm hoping it's because of that
