title: XPathSelectElement always returns null
body: <p>Why is this Xpath not working using XDocument.XPathSelectElement?</p>
  
  <p>Xpath:</p>
  
  <pre><code>//Plugin/UI[1]/PluginPageCategory[1]/Page[1]/Group[1]/CommandRef[2]
  </code></pre>
  
  <p>XML</p>
  
  <pre><code>&lt;Plugin xmlns="http://www.MyNamespace.ca/MyPath"&gt;
    &lt;UI&gt;
      &lt;PluginPageCategory&gt;
        &lt;Page&gt;
          &lt;Group&gt;
            &lt;CommandRef&gt;
              &lt;Images&gt;
              &lt;/Images&gt;
            &lt;/CommandRef&gt;
            &lt;CommandRef&gt;
              &lt;Images&gt;
              &lt;/Images&gt;
            &lt;/CommandRef&gt;
          &lt;/Group&gt;
        &lt;/Page&gt;
      &lt;/PluginPageCategory&gt;
    &lt;/UI&gt;
  &lt;/Plugin&gt;
  </code></pre>
  
  <p>C# Code:</p>
  
  <pre><code>myXDocument.XPathSelectElement("//Plugin/UI[1]/PluginPageCategory[1]/Page[1]/Group[1]/CommandRef[2]", myXDocument.Root.CreateNavigator());
  </code></pre>