Are you looking at the assemblies in the "Program Files\\Reference Assemblies" folder? Those assemblies have the XML doc-comments, but are just empty stubs for Intellisense. The real assemblies are in the "Windows\\Microsoft.NET\\Framework" folder.
Thanks for the question pchristm. If you need any more help please see the new Q&A style support forum over at forums.reflector.net. This is the new place for technical help from our developers and other well respected members of the Reflector community like Richard.