Problem configuring WCF Service bus endpoint

I'm trying to configure an existing WCF service, made with Visual Studio 2010 and Net Framework 4.0, to have a new Service Bus End Point.

I have done next steps (reference:

http://azure.microsoft.com/en-us/documentation/articles/service-bus-dotnet-how-to-use-relay/

):

1. I have created a "Service Bus" in Azure

2. In my WCF Project I have added the "Service Bus" package using the Manage Nuget Packages. This modified the App.config of my WCF service.

3. I have modified the App.config like this:

    <service name="WCFNom.WCFNom">

      <!--existing endpoint -->     

       ...

       <!--new endpoint-->

       <endpoint contract="WCFNom.IWCFNom"
                  binding="netTcpRelayBinding"
                  address="sb://wcfpib.servicebus.windows.net/WCFNom"
                  behaviorConfiguration="sbTokenProvider"/>

       </endpoint>

...

<behaviors>

  <endpointBehaviors>

      <behavior name="sbTokenProvider">

          <transportClientEndpointBehavior>

              <tokenProvider>

                    <sharedAccessSignature keyName="RootManageSharedAccessKey" key="..." />

              </tokenProvider>

          </transportClientEndpointBehavior>

      </behavior>

  </endpointBehaviors>

</behaviors>

When I test the WCF the next error appears:

System.Configuration.ConfigurationErrorsException: The type 'Microsoft.ServiceBus.Configuration.TransportClientEndpointBehaviorElement, Microsoft.ServiceBus, Culture=neutral, PublicKeyToken=31bf3856ad364e35' registered for extension 'transportClientEndpointBehavior' could not be loaded.

Can you help me?

Thans,

Eva Janakieff