title: Mouse.DirectlyOver working incorrectly when mouse with pressed left button is dragged out
body: <p>When mouse is <em>rapidly</em> dragged out of the window with <strong>left button pressed</strong> <code>Mouse.DirectlyOver</code> returns <code>System.Windows.Controls.Grid</code> instead of <code>null</code>.</p>
  
  <p><code>Window.IsMouseOver</code> returns <code>true</code></p>
  
  <p><code>new Rect(window.RenderSize).Contains(Mouse.GetPosition(window))</code> returns <code>true</code></p>
  
  <p>To reproduce that, simply add checking timer to <code>MainWindow()</code> in a blank wpf project like that:</p>
  
  <pre><code>    public MainWindow()
      {
          InitializeComponent();
          var timer = new System.Threading.Timer(state =&gt;
              Dispatcher.BeginInvoke(new Action(
                  () =&gt; Debug.WriteLine("Mouse.DirectlyOver = {0}", Mouse.DirectlyOver)
                  )),null,0,10);
      }
  </code></pre>
  
  <p>When i drag out <em>slowly</em>, the values are correct.</p>
  
  <p>Is there a workaround for that? What is the coorect way to determine mouse is out of the application?</p>