I'm getting a runtime exception at the instant I grab a DragSource item with the mouse and start to move it.

I only get this when I've set the following on my DropTargets:

        dropTarget.DropTargetStyle = (Style)this.Resources["HoverOverStyle"];

My Style Resource is set as follows:

<UserControl.Resources>
  <Style x:Key="HoverOverStyle" TargetType="ContentControl">
    <Setter Property="Background" Value="Yellow"/>
  </Style>
</UserControl.Resources>

The Exception is: System.Windows.Markup.XamlParseException:

Please see the attached file, DropTargetStyle.zip, for detail about the exception.