.NET RIA Services - DataService problem

I downloaded an example of the application based on the .NET RIA services from the article: http://blogs.msdn.com/brada/archive/2009/07/22/business-apps-example-for-silverlight-3-rtm-and-net-ria-services-july-update-part-6-poco-and-authentication-provider.aspx from the "download the full demo files" link.

On my PC (MS VS 2008, SP1, NET RIA Services for vs2008) it is not compilable. I have the following error on attempt to compile application:

Error 2 The type or namespace name 'DataService' could not be found (are you missing a using directive or an assembly reference?) D:\Temp\RIA\MyApp.LiveSite\MyApp.Web\WebDataService.svc.cs 12 35 MyApp.Web Error 3 The type or namespace name 'IDataServiceConfiguration' could not be found (are you missing a using directiv开发者_C百科e or an assembly reference?) D:\Temp\RIA\MyApp.LiveSite\MyApp.Web\WebDataService.svc.cs 15 46 MyApp.Web and a lot of others...

Do you know what is a source of these errors? Am I need to install anything else?

Thanks

Ensure you have .NET 3.5 SP1 installed. I believe System.Data.Services namespace is part of .NET 3.5

Additionally, does the project include a reference to System.Data.Services?