Drop down menus disable the top level navigation item

Hi guys,
when i have a number of pages that use a parent page, the parent page is clickable (contains a URL link).

For my users this is confusing as they expect to only click on the sub page menu items.

How do i achieve this functionality?

(do i need to manually create the navigation menu and then assign pages to it instead of using the create pages method for creating the top navigation menu?)