Sticky Header - Menu moves tight together

Hi There,
two days ago I purchased the Be-theme. So far it is really great! Thanks a lot!
But I have one problem: I decided for a sticky header. But when I scroll down, all the links in the top-menu (classic menu style), move tight together, wich doesn´t look that good. I could not find a solution to fix it. Please take a look at this site:  http://www.axel-steinmueller.de/moderation.
I would be happy to hear from you.
Thank you and best wishes
Axel