Binding a trigger on a rectangle to dependency property of enclosing parent

[Chuck844]

I have used CodeProject as a resource for a long time but now I have an issue I haven't been able to work through ... I have a user control "uc_SignalHead_cl" that is derived from "uc_TrackDisplayItem_cl" which is derived from "UserControl". In uc_SignalHead_cl is a rectangle that I want to change the fill color based on the "SignalDispatchState" dependency property that is defined on "uc_SignalHead_cl". I do not get any runtime binding errors but the fill color is not changing. I know that the dependency property is changing because a "property changed" even is being executed. XAML (some code deleted for clarity):

    <---deleted code--->
    
        

            
                
                    
                        <Setter Property="StrokeThickness" Value="1"/>
                        <Setter Property="Opacity" Value="0.5"/>
                        <Style.Triggers>
                            <Trigger Property="IsMouseOver" Value="True">
                                <Setter Property="StrokeThickness" Value="9"/>
                                <Setter Property="Opacity" Value="1.0"/>
                            </Trigger>
                            <DataTrigger Binding="{Binding SignalDispatchState, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}}}" Value="DS\_Normal">
                                <Setter Property="Fill" Value="Blue"/>
                            </DataTrigger>
                            <DataTrigger Binding="{Binding SignalDispatchState, Re</x-turndown>