There is a bug in the LdapAuth class shown in Chapter 12. Essentially, you must enable Fast Concurrent Binding before attempting to bind to any LdapConnection. Since the sample was reusing the bootstrapping connection it would never work. This only affected code that attempted to use FCB over SSL.
The C# "Full Samples" have been updated and the VB.NET samples will be updated shortly.
Ryan Dunn
Extemporaneous MumblingsThe .NET Developer's Guide to Directory Services Programming