Margin messed up with position:fixed toolbar, but only using "reload/refresh"

Margin messed up with position:fixed toolbar, but only using "reload/refresh"

I'm rather frustrated by this one and can't see anyone else with the same issue, so I've obviously messed something up...

I have a fairly simple JQM page I am displaying.
This page is a single page, with a fixed position header and some content.
When I navigate to this page (ajax or not), or type the URL in and push enter, it loads and everything is right with the world.
However, when I push the reload/refresh button in the browser, the content loses the appropriate top margin and is obscured by the header bar.

This happens on android phone browser, and chrome on my desktop.

The interesting thing, if I click/touch somewhere to make the header bar hide and then again to show it, the margin gets fixed.

I'm using Jquery 1.9.1 and JQM 1.3.0. I do have my own style from themeroller, and am using the -structure thing, but testing without that it still does the same thing...