System.Configuration.ConfigurationErrorsException raised   

I've build a small sample WCF server (.exe). I'm using app.config to set it 
up.  When I start the application, I receive multiple first chance exception:
System.Configuration.ConfigurationErrorsException occurred
  Message="This element is not currently associated with any context"
  Source="System.Configuration"
  BareMessage="This element is not currently associated with any context"
  Line=0
  StackTrace:
       at System.Configuration.ConfigurationElement.get_EvaluationContext()
  InnerException: 

My app.config is:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <system.serviceModel>
    <services>
      <service
          name="Zetec.Core.MessagingService"
          behaviorConfiguration="MessagingServiceBehavior">
        <host>
          <baseAddresses>
            <add 
baseAddress="http://localhost:14899/ServiceModelSamples/Service"/>
          </baseAddresses>
        </host>
        <endpoint address="MessagingService"
                  binding="wsDualHttpBinding"
                  contract="Zetec.Core.IMessagingService" />
        <endpoint 
address="net.pipe://localhost/servicemodelsamples/service/MessagingService"
                  binding="netNamedPipeBinding"
                  contract="Zetec.Core.IMessagingService" />
      </service>
    </services>
    <!--For debugging purposes set the includeExceptionDetailInFaults 
attribute to true-->
    <behaviors>
      <serviceBehaviors>
        <behavior name="MessagingServiceBehavior">
          <serviceMetadata httpGetEnabled="True"/>
          <serviceDebug includeExceptionDetailInFaults="true" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>
</configuration>

The exception does not contain any information to help me debug this.  I 
have 2 questions:
- What is the error in my app.config?
- How do you debug this kind of exception?  I don't have any clue where to 
look for.

Thank in advance
-- 
Stephane Guerin

date: Mon, 17 Mar 2008 04:36:03 -0700   author:   Stephane Guerin