jquery mobile fix footers not really fixed

jquery mobile fix footers not really fixed

So I have a webpage I made using jquery mobile with some graphics that are about 700x650 pixels in size. Its target is for iPad so I know that at that size, they should fit fine on the screen without having the scroll or anything. Now the footers have a data-position="fixed" but I've noticed that they show a little bit of the page background when they are first loaded but when you tap the screen, they then sit at the bottom of the page, as a fixed footer should. Any ideas on why this is happening? Could it be my graphics are too big?