How to serialize/deserialize generated WCF proxy code?

Question

I am trying to serailize/deserialize generated WCF web service proxy code from svcutil. While I'm able to serialize the objects, I'm not able to deserialize them back to objects. Here's the XML I generated through serialization:

<RootObject xmlns="http://schemas.myco.com/online/sync/2008/11"&gt;
    <WrapperObject>
        <Objects>
            <SomeObject p4:type="Foo" ContextId="d5f9f021-b2a1-47ba-9f25-1e068194dc87" ObjectId="fad3ef87-3944-459d-b45b-1e4e52ef24db" xmlns:p4="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.myco.com/online/sync/2008/11" />
        </Objects>
      </WrapperObject>
</RootObject>

I have a couple questions:

1. I am already using XmlSerializerNamespaces to declare the namespace to match the namespace specified in the generated proxy code. How come there is still a "p4" tag that it added to the "SomeObject" tag and a new xml namespace added (xmlns:p4="http://www.w3.org/2001/XMLSchema-instance").

       using (XmlWriter xmlWriter = XmlWriter.Create(stringBuilder, xmlSettings))
       {
           XmlSerializerNamespaces namespaces = new XmlSerializerNamespaces();
           namespaces.Add(string.Empty, defaultNamespace);
   
   
       XmlSerializer serializer = new XmlSerializer(typeof(T), defaultNamespace);
       serializer.Serialize(xmlWriter, objectToBeSerialized, namespaces);
   
   
       return stringBuilder.ToString();
   }
   
   
   

2. When I try to deserialize the XML with the following code, I get the following error: "System.InvalidOperationException: There was an error generating the XML document. ---> System.Xml.XmlException: 'p4:type' is a duplicate attribute name."

       using (TextReader textReader = new StringReader(xmlString))
       {
           using (XmlReader xmlReader = XmlReader.Create(textReader))
           {
               XmlSerializer serializer = new XmlSerializer(typeof(T), defaultNamespace);
               return (T)serializer.Deserialize(xmlReader);
           }
       }
   

3. The proxy code is generated by svcutil to communicate with a WCF web service. All generated objects are serialized/deserialized properly when I just use the web service call.

Has anyone had similar problems before?