WPF WebBrowser Control - position:fixed Element jumps while scrolling (Windows 8)

Question

We use the WPF WebBrowser control to display an embedded page. On Windows 8 we observe a strange jumping behavior of elements with css position:fixed while scrolling.

Answer 1

If there are discrepancies in behavior of the same web page loaded into WebBrowser control and standalone IE browser, the problem can often be fixed by implementing WebBrowser Feature Control.

Once the feature control has been implemented, it makes sense to verify that is observed by WebBrowser and the page is actually rendered in HTML5 standard mode, here's how.

[UPDATE] The OP's sample page actually renders correctly when FEATURE_BROWSER_EMULATION is set to 9000 and the META tag is fixed to be (content="IE9" is not a valid value).