Thanks a lot for your quick answer. I wasn't sure what exactly do you mean with
#contentMainWrapper {clear:both} ?

So I deleted the #contentMainWrapper in the stylesheet.css, but I guess that was wrong because it didn't help.

here is a link to the website, that makes it much easier I guess

http://www.hr-us.com/index.php?main_page=index&cPath=51

Thank you so much for your help

Seville