Children of views menu items don't show

I've troubles to get the children of a menu-item that links to a URL from a view.
What have i done :
- Create a view that is called 'team/members' and accepts parameters. (So for example the URL 'team/members/20' gives me a filtered list)
- Create a menu-item 'team' that point to 'team/members' and put it on the first level in the primary links.
- Create a menu-item 'seniors' that points to 'team/members/20' and put it on the second level in the primary links, as a child of 'team'.
- At last i've created 2 normal content items and put them as children of 'seniors'

The first levels of the primary links are displayed like tabs and the second level (+) are display within a block on the left side of my website.
When i click on 'team', the correct menu on the left site appears (with the 'seniors' menu item unfolded)
But when i click on 'seniors', then i get the right result in the content area, but i don't see the children of 'seniors'.

any ideas why these children don't appear ?