title: Strange rendering issue using WPF within a WinForm
body: <p>I'm displaying a WPF <code>UserControl</code> (which contains a <code>DataGrid</code> and another <code>UserControl</code> for paging) on a <code>WinForm</code> inside an <code>ElementHost</code>. when I display that form and it attempts to render it to the GUI I get the following error </p>
  
  <pre><code>UIElement.Measure(availableSize) cannot be called with NaN size
  </code></pre>
  
  <p>I have checked and none of the Size objects are null or have unexpected values. </p>
  
  <p>What is confusing me is that if I display a <code>MessageBox</code> right before the call then the form renders perfectly. The same <code>UserControl</code> also renders perfectly on a different <code>WinForm</code> and works perfectly when testing on my Win8 pc but not on a Win7 server, any ideas would be appreciated!</p>
  
  <p>Thanks.</p>