Always create new books, except for when "Add child page" selected

I like the preference to create a new book for certain content types automatically, but it seems like if you add a child page with the same content type, that it shouldn't try to create another book in this case. It should act as normal and place the child page in the book you're in. What happens now is that a new book is created with the parent item set to the page you selected the "add" link from.