Menu structure

I have a problem with the substructure of the menu in the desktop version. Is it possible to get alway visible because i have quit large menu’s and submenu’s who are not al visible at the desktop.

For emor info go to http://www.wodanahoeve.nl and choose menu “nakomelingen” and see what happens if you go to “P-nest”. The substructure should give 7 names ut i cab;t get them on the screen.

The page I need help with: [log in to see the link]