Hi, I'm trying to show a different image when the button is disabled. Should be easy with triggers, right?!

For some reason, I have not been able to get the images to switch. I've tried setting triggers on both the image and button. What is wrong with what I have below? How can I change the image source when the button is enabled/disabled?

Thanks!

<Button
         x:Name="rleft"
         Command="{Binding Path=Operation}"
         CommandParameter="{x:Static vm:Ops.OpA}">
            <Button.Content>
                <StackPanel>
                    <Image
                  Width="24"
                  Height="24"             
                  RenderOptions.BitmapScalingMode="NearestNeighbor"
                  SnapsToDevicePixels="True"
                  Source="/MyAssembly;component/images/enabled.png">
                        <Image.Style>
                            <Style>
                                <Style.Triggers>
                                    <DataTrigger Binding="{Binding ElementName=rleft, Path=Button.IsEnabled}" Value="False">
                                        <Setter Property="Image.Source" Value="/MyAssembly;component/images/disabled.png" />
                                    </DataTrigger>
                                </Style.Triggers>
                            </Style>
                        </Image.Style>
                    </Image>
                </StackPanel>
            </Button.Content>
        </Button>