dropdown submenu on same level

Hello,
I am completely new to wrodpress. I use Atahualpa 3.4.9 theme.

I probably did a wrong thing and cannot repair it. The dropdown submenus are now at the same level than the first dropdown menu. also, I use to have arrow going down in the page bar menu, but they disappared; but I don't know whether this is linked.
See http://www.esf.be/new/

It is already now two days that I am trying to sort this out. But the more it gors, the more I go crasy, so allow me to turn to anyone who would be nice to help.

My settings in "configure header area" is: %logo %bar1 %image %pages %bar2

I read many threads on the forum, and tried many solutions, but none worked.

I would appreciate any support and am ready to donate.

many thanks in advance, Pascal