title: Design Time Error - 'VisualState' occurs in at least two namespaces
body: <p>I am getting the following error</p>
  
  <p><em>Ambiguous type reference. A type named 'VisualState' occurs in at least two namespaces, 'System.Windows' and 'System.Windows'. Consider adjusting the assembly XmlnsDefinition attributes.</em></p>
  
  <p>I am not referencing any of these assembly name spaces directly, I am doing the following:</p>
  
  <pre><code>&lt;ResourceDictionary
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"   
  </code></pre>
  
  <p>The application compiles fine, just throwing these errors at design time.  This happens to a few other classes that are a part of the VSM library.</p>