[support] Custom menus and nested menu items not displaying

I created a new menu and when I create nested content within the menu it doesn't show the sub-items when you click on a parent item. If I check the "Show as Expanded" for the parent then the sub-items do display. If it's not checked the parent shows with an arrow indicating it has children. but when you click on the parent link the children do not display. If I change the parent to be assigned to Navigation instead of my new menu then it works fine.

When I click list links for the menu in admin it shows the proper child/parent relationships. Is there something I have to enable for a new menu to make it display like the navigation menu does for nested content?

Thanks,

Adam