Access control hierarchy?

After searching the web, reading my books and even some trial and error I thought I would post this (should be) rather simple access question to this group for all you eager Drupal experts to laugh at me and respond in kind:

I have created a book page (our content type) that only a very few users should have access to. This page is assigned to a book via the outline select list. I've created a new descriptive role and set this role as required in the access control section of this book page. Then I accessed each designated user and set their respective role. As with other book pages w/outlines, the page(s) available appear in the left-side book menu IF the user is so authorized.

I tested this by masquerading as each of the few such users and it appeared to work. Masquerading as someone without this role and the menu item is not there. Great! However, when those users are logged on themselves this page does NOT appear in the left book menu so it is therefore not available to them. When I look at the overall permissions for the particular page, under the View column there are other roles already checked and protected (grayed out). My question is: where did these other already checked and protected roles originate? Content type? Any way to override them? Does anyone have a better method to approach this? Or am I just missing something?

BTW - maybe a good review topic for one of our meetings is a roles/rules overview and it appears more and more sites are requiring much more granular access control.

Thanks - Bob