iFramed position:fixed container box not viewport on tab refocus

Hi, my iFramed document contains a position:fixed element inside the scrolled body. It works great in Safari when the page first loads. But tab away and back to the page, and the position:fixed element is hidden at the top of the page. Strangely, the Safari inspector "sees" the position:fixed element back in the viewport area. The position:fixed element's bounding box is registered in the fixed:position where the element should be visible. But, the position:fixed element is not visible there, its hidden at the top. It only snaps into the viewport if the body is manually scrolled. Attempting to scroll the body with javascript does not show the position:fixed item in the viewport. This is only an issue in Safari, FF and Chrome show the item in it's fixed position after the page gets focus again.