title: Html Agility Pack returns invalid XPath
body: <p>I have an HTML document opened in two windows, and I need the selected node to be synchronized between both windows.</p>
  
  <p>Using <a href="http://htmlagilitypack.codeplex.com/" rel="nofollow">Html Agility Pack</a> I tried:</p>
  
  <pre><code>HtmlNode myNode = GetSomeCertainNode();
  
  string xpath = myNode.XPath; //xpath = "/#comment[1]"
  
  // This line throws an XPathException
  var reExtract = myNode.OwnerDocument.DocumentNode.SelectSingleNode(xpath);
  </code></pre>
  
  <p>Exception message: <code>'/#comment[1]' has an invalid token.</code></p>
  
  <p>I'm wondering, I took the XPath from the node itself, which means it's a proper XPath, and I use it against the same document, why does it fail, what do I miss?</p>
  
  <p><strong>Update</strong></p>
  
  <p>When selecting some other nodes I get this exception instead: <code>Expression must evaluate to a node-set.</code> (<code>xpath</code> contains <code>/html[1]/body[1]/div[1]/p[3]/strong[1]/#text[1]</code>).</p>
  
  <p>But remember that the value is taken from the node itself, therefore it's very weird. How come it's complaining that it's invalid?</p>