title: Issues with {RelativeSource PreviousData} when removing collection elements
body: <p>I'm using the following (simplified) code to display an element in all the items in an ItemsControl except the first:</p>
  
  <pre><code>&lt;TheElement Visibility="{Binding RelativeSource={RelativeSource PreviousData},
                                   Converter={StaticResource NullToVisibility}}/&gt;
  </code></pre>
  
  <p><code>NullToVisibility</code> is a simple converter that returns <code>Visibility.Hidden</code> if the source is null, <code>Visibility.Visible</code> otherwise.</p>
  
  <p>Now, this works fine when binding the view initially, or adding elements to the list (an <code>ObservableCollection</code>), but <strong>the element is not made invisible on the second element when removing the first</strong>.</p>
  
  <p>Any ideas on how to fix this?</p>