Sub menu in IE displayed behind featured video

Hi,

In Internet Explorer I've a problem with a submenu disapearing behind the featured video.
When you go to the website and hover your mouse over NIEDORP in the top menu bar you can see the submenu disappears behind the video. Or take a look at the screen dumps showing a okay submenu and a not okay submenu.

Within Firefox the submenu is displayed okay.

How can I fix this for Internet Explorer?

Greetings,
Age