Problem with Menus

I am having problem with displaying of links at my secondary navigation pages.

What happens is that When I go to Secondary navigation by clicking on a link at primary navigation content, the active class for primary menu is lost.

I found a solution to that. I solved that by calling menu_set_active_item() function in _phptemplate_variables() function in my template.php file. The link now does remain selected. But this raises another major problem that the Edit tabs from local tasks menu are now lost.

I tried so many things but not able to understand how can I do this.

One more question is: When I create a new content of some content type, Do I strictly need to add that content item to my submenu, only then It will select the coreesponding primary menu item as selected or adding link to menu is optional.

Any help will be really appreciated.