Can't find a specific forum for this book ... so ...
Page 39 & 41 contains a line of code that needs some errata or additional support material.
var feed = System.ServiceModel.Syndication.SyndicateFeed.Load (reader);
generates a Type or Namespace Error. ServiceModel does not exist in NameSpace System.
Adding a reference to the ServiceModel does not help.
See this URL (comment by James Morey) for a fix: http://msdn.microsoft.com/en-us/libr...8VS.95%29.aspx
In short, SL4.0 does not have a reference to this in the System NameSpace.