title: Windows Phone ListBox Item Background Changing Color Even Though It's Set Explicitely
body: <p>I am looking for 1) what is going on, and 2) how to fix the issue.</p>
  
  <p><strong>Issue</strong></p>
  
  <p>If a ListBox Item height is above 2521, it seems to change the background to black even when the background is explicitly set to something else. </p>
  
  <p><strong>How To Reproduce</strong></p>
  
  <p>Take the sample XAML file I have below, and in your xaml.cs file add the following:</p>
  
  <pre><code>DataContext = new List&lt;int&gt;() { 1 };
  </code></pre>
  
  <p>Change the height of the TextBlock to 2522 or higher.</p>
  
  <p>The sample code is not where I encountered the issue, however it is a simple example to demonstrate the bug. I am not planning on having a TextBlock that is 2522+ in size :)</p>
  
  <p><strong>Sample XAML file</strong></p>
  
  <p></p>
  
  <pre><code>    &lt;Grid x:Name="LayoutRoot" Background="Brown"&gt;
          &lt;Grid.RowDefinitions&gt;
              &lt;RowDefinition Height="*"/&gt;
          &lt;/Grid.RowDefinitions&gt;
  
          &lt;phone:Pivot x:Name="pivot" Title="{Binding name}" Grid.Row="1" Foreground="White" Margin="10,0,0,0"&gt;
              &lt;phone:PivotItem x:Name="mainPivot" Header="menu" Margin="0,0,20,0"&gt;
                  &lt;ListBox ItemsSource="{Binding}"&gt;
                      &lt;ListBox.ItemTemplate&gt;
                          &lt;DataTemplate&gt;
                              &lt;Grid Background="White"&gt;
                                  &lt;StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28"&gt;
                                      &lt;TextBlock Height="2521" Text="some data" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}" FontSize="22" Foreground="Purple"/&gt;
                                  &lt;/StackPanel&gt;
                              &lt;/Grid&gt;
                          &lt;/DataTemplate&gt;
                      &lt;/ListBox.ItemTemplate&gt;
                  &lt;/ListBox&gt;
              &lt;/phone:PivotItem&gt;
  
          &lt;/phone:Pivot&gt;
  
      &lt;/Grid&gt;
  &lt;/phone:PhoneApplicationPage&gt;
  </code></pre>
  
  <p><strong>Remarks</strong></p>
  
  <p>A few people have raised concerns about my UI. The above code is a <em>sample</em> and not my actual UI. There are no performance issues and the ListBox is not sluggish. Everything works as expected except the background changes color.</p>