menuparent class in li also set if childs are hidden (layout problems)

When i set up my nice menu block showing only first and second level and hiding all deeper childs, the menuparent css class will be set to all those menu-items which have hidden childs. this will result in layout problems due to shown arrows, indicating a submenu (which is not shown ).

For example:
I have this menu tree:

- Home
- About
- - Entertainment
- - - DJs
- - - VJs
- - - Dancers
- - Production
and so on.

now only first and second level should be shown, the childs DJs, VJs etc should be hidden.

The resulting code for "Entertainment" Item is:

But the menuparent class should not be added in this case, and the arrow for submenu-indication should be hidden. See attached image.