How to hide detailed navigation for some roles ?

Hello All

I would like to hide the DTN panel for some of the roles in our portal, its 7.4 SP11. The role structure is Role - Workset - Pages/Views

I am using the Ajax Framework Page

For the iViews/Pages, the property 'initial state of Navigation Panel " is set to Always Close.

But still the navigation panel appears. Is there any other settings to be maintained?

Regards

Aakash