title: WPF Frame control with source property always on top?
body: <p>Given the following little snippet:</p>
  
  <pre><code>&lt;Grid&gt;
    &lt;Frame Width="300" Height="300" Background="Blue"&gt;&lt;/Frame&gt;
    &lt;Frame Width="350" Height="350" Background="Red"&gt;&lt;/Frame&gt;
  &lt;/Grid&gt;
  </code></pre>
  
  <p>as expected you don't get to see the blue frame (it being behind the red one).</p>
  
  <p>However, if you include the source attribute to the blue frame:</p>
  
  <pre><code>&lt;Grid&gt;
    &lt;Frame Width="300" Height="300" Background="Blue" Source="c:\test.htm"&gt;&lt;/Frame&gt;
    &lt;Frame Width="350" Height="350" Background="Red"&gt;&lt;/Frame&gt;
  &lt;/Grid&gt;
  </code></pre>
  
  <p>it pops itself to the front. </p>
  
  <p>Any idea why and can I prevent it?</p>
  
  <p>thanks</p>