While most Studio for WPF products are fully functional in an XAML Browser Application (XBAP), Book for WPF does not include XBAP functionality in a partial trust environment. Book for WPF uses shader effects for the shadows in the book display and shader effects are unfortunately not allowed in a WPF partial trust environment.

To run an application as full trust, you can open the application's properties, and select This is a full trust application from the Security tab. For full instructions, see http://blogs.microsoft.co.il/blogs/maxim/archive/2008/03/05/wpf-xbap-as-full-trust-application.aspx.