Disappearing css menu in asp

Maybe someone can help me out. I've asked (and deleted) the question in another tread (css) with no response.

As a hobby I'm working on a website for a youth circus in the Netherlands.

I've made a dropdown menu with a css. It is working fine as you can see at:

http://www.santelli.nl/index2.htm

Since we are changing the menu every now and then, I've build a seperate htm file (and as an experiment also a txt file) with the menu structure. In asp I use an 'include' to show it in the page. In doing so I save a lot of work when the menu needs a change.

My work resulted in:

http://www.santelli.nl/test2cssmettextfile.asp

It looks okay, but when hovering down over the second level menu the dropdown in the second (asp) version disappears for some reason.

I don't have a clue how to solve this problem.

Can someone help me out?