Book Access seems to have no effect

I am attempting to use book_access to grant editing and creation permissions to users by role, but it does not seem to be having any effect. Here is how I set it up:

- Installed book_access
- Enabled book_access in Modules
- Created a book called "Lower School" with a number of child nodes, all using the Page content type
- Enabled the book navigation menu for this book
- Created a role called "editor - lower school"
- Created a new user and assigned it to the role "editor - lower school"
- Assigned "Edit pages in this book" and "Delete pages in this book" to the role "editor - lower school"

When this user goes to the pages in the Lower School book, he cannot see the create child page link or the edit tab. If I give the role permission to create, edit, or delete nodes of the Page content type, then the user can do that throughout the entire site, not just in the specified book. As far as I can tell, book_access is having no effect on permissions.

I have rebuilt node access permissions under Post Settings. My node_access table looks extremely uniform, with all nodes in the site like this: gid realm grant_view grant_update grant_delete
0 all 1 0 0

I am running Drupal 6.8 with the following third-party modules installed:

autosave fckeditor ldap_integration scheduler
book_access filefield lightbox2 simplemenu
calendar messaging slideshow
cck image token
date notifications unused
devel image_fupload og views
emfield jquery_media print

Thank you for your help!

Richard