Highlight active category / page item in menus

Hello,

I'm continuing to discover the power of the Atahualpa theme.

I don't know how to keep highlighted the current active item in the page menu bar. I used a plugin named "PostLists", that creates some placeholders so I can post posts into pages.
Is there a way that the tab related to the parent page, that hosts some posts, keep being highlighted as active when one of these posts is displayed?
I also have the same needs related to the sidebar menu: I used the Wordpress Navigation List Plugin NAVT, and I'd like the active category to remain highlighted when we read one of the posts that are in.

Hope my question is sufficiently clear...

Thanks a lot for your help!

Vincent