Hi Christoph,

In this case, you are using URL's that already exist in the menu. If you look at your first screenshot, you will see that the "Calendar" menu option has been selected (as you are using that URL). In the second screenshot, the "courses" option has the selected CSS class (again as you are using that URL).

I suspect that if you use a URL that is not already in the menu, you sill see the item you select will have the "selected" CSS class.

Cheers,

Brian Barnes