When the message body is string, I can dequeue the message.  But when I change the message body to a data structure, say, 
  public struct Customer
  {
    public string Last;
    public string First;
  }
I encounter the following error stack trace
   at System.Type.GetType(String typeName, Boolean throwOnError)
   at System.Messaging.XmlMessageFormatter.CreateTargetSerializerTable()
   at System.Messaging.XmlMessageFormatter.Read(Message message)
   at System.Messaging.Message.get_Body()
I have correctly set the message's formatter to be 
new XmlMessageFormatter(new String[] {"Customer", "customer"})
where "customer" is the name of assembly containing the Customer struct.
The message is taken from the queue.  This error appears when I try to either typecast message's body or directly printout its body.toString().  Has anyone encountered this error b4?  Any idea?
Many thanks