Vista - Triggers Firing for Child Objects

I am trying to make an animated Expander, that slides open and closed.
It works fine, however when in put another Expander inside it, the
triggers/routed events seem to get a little confused. When the child
Expander is closed, it runs the CollapseMe Storyboard on the parent
(even if the child doesn't have the Animated Template). Of course I
don't want this to happen, because it's just weird.

Can anyone help me please

Cheers



<Window x:Class="WpfTest.Window4"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="WpfTest" Height="343" Width="407"
>
<Window.Resources>
<ControlTemplate x:Key="AnimatedExpander" TargetType="Expander">
<ControlTemplate.Resources>
<Storyboard x:Key="ExpandMe">
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00"
Duration="00:00:00.150"

Storyboard.TargetName="ContentBorder"

Storyboard.TargetProperty="(FrameworkElement.LayoutTransform).
(TransformGroup.Children)[0].(ScaleTransform.ScaleY)">
<LinearDoubleKeyFrame KeyTime="00:00:00.150" Value="1"/>
<DiscreteDoubleKeyFrame KeyTime="00:00:00.150" Value="1"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
<Storyboard x:Key="CollapseMe">
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00"
Duration="00:00:00.150"

Storyboard.TargetName="ContentBorder"

Storyboard.TargetProperty="(FrameworkElement.LayoutTransform).
(TransformGroup.Children)[0].(ScaleTransform.ScaleY)">
<LinearDoubleKeyFrame KeyTime="00:00:00.150" Value="0"/>
<DiscreteDoubleKeyFrame KeyTime="00:00:00.150" Value="0"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</ControlTemplate.Resources>
<StackPanel>
<ToggleButton Name="Header"
IsChecked="{Binding Path=IsExpanded,
Mode=TwoWay,
RelativeSource={RelativeSource
TemplatedParent}}"
Padding="0">
<ContentPresenter
Margin="4"
ContentSource="Header"
RecognizesAccessKey="True" />
</ToggleButton>
<Border Name="ContentBorder"
BorderBrush="LightGray"
BorderThickness="1"
Height="Auto">
<Border.LayoutTransform>
<TransformGroup>
<ScaleTransform ScaleX="1" ScaleY="1"/>
<SkewTransform AngleX="0" AngleY="0"/>
<RotateTransform Angle="0"/>
<TranslateTransform X="0" Y="0"/>
</TransformGroup>
</Border.LayoutTransform>
<ContentPresenter Margin="10"/>
</Border>
</StackPanel>
<ControlTemplate.Triggers>
<EventTrigger RoutedEvent="Expander.Expanded">
<EventTrigger.Actions>
<BeginStoryboard Storyboard="{StaticResource ExpandMe}"/>
</EventTrigger.Actions>
</EventTrigger>
<EventTrigger RoutedEvent="Expander.Collapsed">
<EventTrigger.Actions>
<BeginStoryboard Storyboard="{StaticResource CollapseMe}"/
>
</EventTrigger.Actions>
</EventTrigger>

</ControlTemplate.Triggers>
</ControlTemplate>

</Window.Resources>

<Grid>
<Expander Margin="30,36,45,44" Header="EXPANDER ONE"
IsExpanded="True" Template="{StaticResource AnimatedExpander}">
<Expander Height="120" Padding="4" Background="Gainsboro"
Header="CHILE EXPANDER" Width="160" IsExpanded="False">
<Button></Button>
</Expander>
</Expander>
</Grid>
</Window>