Panels node override for book pages breaks breadcrumbs and menus

If you create a node override for book pages, breadcrumbs and menus stop behaving after you navigate deeper into the book hierarchy.

For example, if I have a book whose root page is called "The Story of Mr. Bubble," the breadcrumbs are fine for that page.

ex. crumbs: Home -> Mr. Bubble Products
ex. page title: The Story of Mr. Bubble

For a deeper item named "Mr. Bubble in the 21st Century" in that book, the breadcrumbs and menu should be:

ex. crumbs: Home -> Mr. Bubble Products -> The Story of Mr. Bubble
ex. page title: Mr. Bubble in the 21st Century

Instead, this is what we get:

ex. crumbs: Home
ex. page title: Mr. Bubble in the 21st Century

Without a node override, the book pages' hierarchy integrate into the menu system through the view operation of book_nodeapi.

With a node override, these operations should be called when the "no extras" box isn't checked for the node content pane, but I think Panels 2 must be setting the menu location and breadcrumbs in some other way, or not setting them at all. That's where I get lost.