APOLLO 11 Nav Bar problem

www.ersted-rasmussen.dk

My nav-bar on the right is behaving badly. When I open a project or a page it disappears. On chrome it reappears and works almost perfectly after reload of page, but on IE it just disappears.

I've tried going through the CSS, but I can't locate the problem.

Also tried exchanging the whole CSS code to this:
http://cargocollective.com/designs/limelight/apollo11/template.css
but with no luck.

Any help will be greatly appreciated.