How do I have to change this XML string so that XDocument.Parse reads it in?

In the following code, I serialize an object into an XML string.

But when I try to read this XML string into an XDocument with XDocument.Parse, it gives me this error:

Invalid data at root level.

The XML is:

<?xml version="1.0" encoding="utf-8"?>
<Customer xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
   <Id>1</Id>
   <FirstName>Jim</FirstName>
   <LastName>Jones</LastName>
   <ZipCode>23434</ZipCode>
</Customer>

UPDATE: Here is the hex:

![alt text][1] Mod edit - disabled hyperlink: links to malware

What do I have to do to this XML so that it reads into the XDocument without an error?

using System;
using System.Collections.Generic;
using System.Xml.Serialization;
using System.IO;
using System.Xml;
using System.Text;
using System.Xml.Linq;

namespace TestSerialize2342
{
    class Program
    {
        static void Main(string[] args)
        {
            List<Customer> customers = Customer.GetCustomers();

            Console.WriteLine("--- Serializing ------------------");

            foreach (var customer in customers)
            {
                Console.WriteLine("Serializing " + customer.GetFullName() + "...");
                string xml = XmlHelpers.SerializeObject<Customer>(customer);

                XDocument xdoc = XDocument.Parse(xml);

            }

            Console.ReadLine();
        }

    }

    public static class StringHelpers
    {
        public static String UTF8ByteArrayToString(Byte[] characters)
        {
            UTF8Encoding encoding = new UTF8Encoding();
            String constructedString = encoding.GetString(characters);
            return (constructedString