Hi,
Below are three attempts at setting a WPF window background. The first two work as expected, the third just shows a black background (although the Title property is changed as expected). Anyone know why the third option fails?

    <!--
    <Window.Background>
        <VisualBrush>
            <VisualBrush.Visual>
                <MediaElement Source="intro.wmv" />
            </VisualBrush.Visual>
        </VisualBrush>
    </Window.Background>
    <Window.Title>Test 1</Window.Title>
    -->
    
    <!--<Window.Style>
        <Style TargetType="{x:Type Window}" >
            <Setter Property="Background">
                <Setter.Value>
                    Red
                </Setter.Value>
            </Setter>
        </Style>
    </Window.Style>
    -->
    
<!--
    <Window.Style>
        <Style TargetType="{x:Type Window}">
            <Setter Property="Title" Value="Using Style for Video" />
            <Setter Property="Background">
                <Setter.Value>
                    <VisualBrush>
                        <VisualBrush.Visual>
                            <MediaElement Source="intro.wmv"/>
                        </VisualBrush.Visual>
                    </VisualBrush>
                </Setter.Value>
            </Setter>
        </Style>
    </Window.Style>
-->

TIA,
Viv
P.S. Hope this shows up OK - I see nothing when looking at it in preview mode here.....