title: WPF <StatusBar> is not positioned at the bottom of the window
body: <p>We have a WPF executable that creates a  and then dynamically loads several assemblies. Each assembly represents a screen (.xaml) that is displayed in one of the tabs. The Problem is that the  is right under the  and not at the bottom of the window. How do I force the  to always be at the bottom of the 
  window? Thx!</p>
  
  <pre><code>UserControl    
      DockPanel
          CheckBox 
          StatusBar
      DockPanel
  UserControl
  </code></pre>