WPF DataTrigger in ControlTemplate

[Flo_Plus]

Hallo,

ich muss schon wieder nerven. Wieder an einer Kleinigkeit wahrscheinlich!
Das ist ein CodeSnipe in XAML:

<ControlTemplate 
    x:Key="{x:Static MenuItem.SubmenuHeaderTemplateKey}" 
    TargetType="{x:Type MenuItem}">
    <Border Name="Border" >
      <Grid>
        <Grid.ColumnDefinitions>
          <ColumnDefinition Width="Auto" SharedSizeGroup="Icon"/>
          <ColumnDefinition Width="*" />
          <ColumnDefinition Width="Auto" SharedSizeGroup="Shortcut"/>
          <ColumnDefinition Width="13"/>
        </Grid.ColumnDefinitions>
        <ContentPresenter 
          Name="Icon"
          Margin="6,0,6,0"
          VerticalAlignment="Center"
          ContentSource="Icon"/>
        <ContentPresenter 
          Name="HeaderHost"
          Grid.Column="1"
          ContentSource="Header"
          RecognizesAccessKey="True"/>
        <TextBlock x:Name="InputGestureText"
          Grid.Column="2"
          Text="{TemplateBinding InputGestureText}"
          Margin="5,2,2,2"
          DockPanel.Dock="Right"/>
        <Path 
          Grid.Column="3"
          HorizontalAlignment="Center"
          VerticalAlignment="Center"
          Data="M 0 0 L 0 7 L 4 3.5 Z" 
          Fill="{StaticResource GlyphBrush}" />
        <Popup 
          Name="Popup"
          Placement="Right"
          HorizontalOffset="-4" 
          IsOpen="{TemplateBinding IsSubmenuOpen}"
          AllowsTransparency="True" 
          Focusable="False"
          PopupAnimation="Fade">
          <Border 
            Name="SubmenuBorder"
            SnapsToDevicePixels="True"
            Background="{StaticResource WindowBackgroundBrush}"
            BorderBrush="{StaticResource SolidBorderBrush}"
            BorderThickness="1" >
            <ScrollViewer CanContentScroll="True"
              Style="{StaticResource MenuScrollViewer}">
              <StackPanel  
              IsItemsHost="True" 
              KeyboardNavigation.DirectionalNavigation="Cycle" />
            </ScrollViewer>
          </Border>
        </Popup>
      </Grid>
    </Border>
    <ControlTemplate.Triggers>
      <Trigger Property="Icon" Value="{x:Null}">
        <Setter TargetName="Icon" Property="Visibility" Value="Collapsed"/>
      </Trigger>
      <Trigger Property="IsHighlighted" Value="true">
        <Setter TargetName="Border" Property="Background" Value="{StaticResource SelectedBackgroundBrush}"/>
      </Trigger>
      <Trigger SourceName="Popup" Property="Popup.AllowsTransparency" Value="True">
        <Setter TargetName="SubmenuBorder" Property="CornerRadius" Value="4"/>
        <Setter TargetName="SubmenuBorder" Property="Padding" Value="0,3,0,3"/>
      </Trigger>
      <Trigger Property="IsEnabled" Value="false">
        <Setter Property="Foreground" Value="{StaticResource DisabledForegroundBrush}"/>
      </Trigger>
    </ControlTemplate.Triggers>
  </ControlTemplate>

Ich möchte einen "DATATRIGGER" einbauen, der wie der Trigger auf das Popup-Control reagiert, und anschließend eine Animation mit dem SubmenuBorder spielt:#

<DataTrigger Binding="{Binding ElementName=Popup, Path=AllowsTransparency}" Value="True">
                 <!--<DataTrigger.EnterActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <ColorAnimation Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" Storyboard.TargetName="SubmenuBorder"
                                            To="Red" Duration="0:0:2"/>
                        </Storyboard>
                    </BeginStoryboard>
                </DataTrigger.EnterActions>-->
            </DataTrigger>

Das funktioniert aber nicht.. Wenn ich das Storyboard mit normalen Settern ersetzte geht es....

MfG