sub menu items not appearing eventhough put under page attribute

I need some help desparately.
I have added a page which has a parent page BUT I find that the sub page does not appear as sub menu item of the parent page in the category menu bar in atahualpa theme version 3.7.3 and wordpress 3.3.1
For example I have a parent page -Boot-camp-series which is a menu item in the category menu bar. The sub page Boot-camp-1 is a page whose parent is boot-camp-series. Eventhough I have set the page attribute for boot-camp-1 as boot-camp-series it does not appear on the category menu bar.

What is the reason for this. Do I need to change any attributes in theme options ?

I can provide the screen shot if needed.