In the first beta a page-corner would sometimes ‘stick’ to the user’s mouse (dubbed the sticky-page bug).
The second bug was that when the user would open the Book and then close it, an Error would be thrown (the book-opening bug)..
Both of the above bugs have been fixed in the second beta, for more information please see the bugs-section in the original beta blog-post.
I also created a very basic usage-example for the Book component. The original demo was meant to show off as many features and as much functionality as possible.
As a side-effect though, the main application MXML-file might give the impression that using the Book component gets really complicated. The contrary is true.