Removing thin border around the menuitems

I based a custom menu on some code I once received. It looks OK, but I'm going crazy over how to remove the thin black border around the entire section of menuitems?! Where is this border/padding defined?

Thanks to any WPF guru that might help me with this :)

Valid XHTML http://img843.imageshack.us/img843/8813/testn.png

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <SolidColorBrush x:Key="HighlightedBackgroundBrush" Color="#003466" />
    <SolidColorBrush x:Key="MenuBackgroundBrush" Color="#003466" />
    <SolidColorBrush x:Key="NormalBorderBrush" Color="#FFFFFFFF" />
    <SolidColorBrush x:Key="SolidMenuFontBrush" Color="#FFFFFFFF" />
    <SolidColorBrush x:Key="HighlightedText" Color="#FFFFFFFF" />

    <Style x:Key="{x:Type Menu}" TargetType="{x:Type Menu}">
        <Setter Property="OverridesDefaultStyle" Value="True"/>
        <Setter Property="SnapsToDevicePixels" Value="True"/>
        <Setter Property="Height" Value="25"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type Menu}">
                    <Border Background="{DynamicResource AppBackground}"
                            BorderBrush="{DynamicResource AppBackground}"
                            BorderThickness="1">
                        <StackPanel ClipToBounds="True" Orientation="Vertical" IsItemsHost="True"/>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <Style x:Key="{x:Type MenuItem}" TargetType="{x:Type MenuItem}">
        <Setter Property="OverridesDefaultStyle" Value="True"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type MenuItem}">
                    <Border x:Name="Border" BorderThickness="1">
                        <Grid Background="{DynamicResource AppBackground}">
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition x:Name="Col0" MinWidth="17" Width="Auto" SharedSizeGroup="MenuItemIconColumnGroup"/>
                                <ColumnDefinition Width="Auto" SharedSizeGroup="MenuTextColumnGroup"/>
                                <ColumnDefinition Width="Auto" SharedSizeGroup="MenuItemIGTColumnGroup"/>
                                <ColumnDefinition x:Name="Col3" />
                            </Grid.ColumnDefinitions>

                            <!-- ContentPresenter to show an Icon if needed -->
                            <ContentPresenter Grid.Column="0" Margin="4,0,6,0" x:Name="Icon" VerticalAlignment="Center" ContentSource="Icon"/>

                            <!-- Glyph is a checkmark if needed for a checkable menu -->
                            <Grid Grid.Column="0" Visibility="Hidden" Margin="4,0,6,0" x:Name="GlyphPanel" VerticalAlignment="Center">
                                <Path x:Name="GlyphPanelpath" VerticalAlignment="Center" Fill="{TemplateBinding Foreground}" Data="M0,2 L0,4.8 L2.5,7.4 L7.1,2.8 L7.1,0 L2.5,4.6 z" FlowDirection="LeftToRight"/>
                            </Grid>

                            <!-- Content for the menu text et开发者_开发百科c -->
                            <ContentPresenter Grid.Column="1"
                                Margin="{TemplateBinding Padding}"
                                x:Name="HeaderHost"
                                RecognizesAccessKey="True"
                                ContentSource="Header"/>

                            <!-- Content for the menu IGT -->
                            <ContentPresenter Grid.Column="2"
                                Margin="8,1,8,1"
                                x:Name="IGTHost"
                                ContentSource="InputGestureText"
                                VerticalAlignment="Center"/>

                            <!-- Arrow drawn path which points to the next level of the menu -->
                            <Grid Grid.Column="3" Margin="4,0,6,0" x:Name="ArrowPanel" VerticalAlignment="Center">
                                <Path x:Name="ArrowPanelPath" HorizontalAlignment="Right" VerticalAlignment="Center" Fill="{TemplateBinding Foreground}" Data="M0,0 L0,8 L4,4 z"/>
                            </Grid>

                            <!-- The Popup is the body of the menu which expands down or across depending on the level of the item -->
                            <Popup IsOpen="{Binding Path=IsSubmenuOpen, RelativeSource={RelativeSource TemplatedParent}}" Placement="Right" x:Name="SubMenuPopup" Focusable="false" PopupAnimation="{DynamicResource {x:Static SystemParameters.MenuPopupAnimationKey}}">
                                <Border x:Name="SubMenuBorder" BorderBrush="{Binding Path=Foreground, RelativeSource={RelativeSource AncestorType={x:Type Menu}}}" BorderThickness="1" Padding="2,2,2,2">
                                    <Grid x:Name="SubMenu" Grid.IsSharedSizeScope="True">
                                        <!-- StackPanel holds children of the menu. This is set by IsItemsHost=True -->
                                        <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Cycle"/>
                                    </Grid>
                                </Border>
                            </Popup>
                        </Grid>
                    </Border>

                    <!-- These triggers re-configure the four arrangements of MenuItem to show different levels of menu via Role -->
                    <ControlTemplate.Triggers>
                        <!-- Role = TopLevelHeader : this is the root menu item in a menu; the Popup expands down -->
                        <Trigger Property="Role" Value="TopLevelHeader">
                            <Setter Property="Padding" Value="6,1,6,1"/>
                            <Setter Property="Placement" Value="Bottom" TargetName="SubMenuPopup"/>
                            <Setter Property="MinWidth" Value="2" TargetName="Col0"/>
                            <Setter Property="Width" Value="Auto" TargetName="Col3"/>
                            <Setter Property="Visibility" Value="Collapsed" TargetName="Icon"/>
                            <Setter Property="Visibility" Value="Collapsed" TargetName="GlyphPanel"/>
                            <Setter Property="Visibility" Value="Collapsed" TargetName="IGTHost"/>
                            <Setter Property="Visibility" Value="Collapsed" TargetName="ArrowPanel"/>
                        </Trigger>

                        <!-- Role = TopLevelItem :  this is a child menu item from the top level without any child items-->
                        <Trigger Property="Role" Value="TopLevelItem">
                            <Setter Property="Padding" Value="6,1,6,1"/>
                            <Setter Property="Visibility" Value="Collapsed" TargetName="ArrowPanel"/>
                        </Trigger>

                        <!-- Role = SubMenuHeader : this is a child menu item which does not have children -->
                        <Trigger Property="Role" Value="SubmenuHeader">
                            <Setter Property="DockPanel.Dock" Value="Top"/>
                            <Setter Property="Padding" Value="0,2,0,2"/>
                        </Trigger>

                        <!-- Role = SubMenuItem : this is a child menu item which has children-->
                        <Trigger Property="Role" Value="SubmenuItem">
                            <Setter Property="DockPanel.Dock" Value="Top"/>
                            <Setter Property="Padding" Value="0,2,0,2"/>
                            <Setter Property="Visibility" Value="Collapsed" TargetName="ArrowPanel"/>
                        </Trigger>
                        <Trigger Property="IsSuspendingPopupAnimation" Value="true">
                            <Setter Property="PopupAnimation" Value="None" TargetName="SubMenuPopup"/>
                        </Trigger>

                        <!-- If no Icon is present the we collapse the Icon Content -->
                        <Trigger Property="Icon" Value="{x:Null}">
                            <Setter Property="Visibility" Value="Collapsed" TargetName="Icon"/>
                        </Trigger>

                        <!-- The GlyphPanel contains the CheckMark -->
                        <Trigger Property="IsChecked" Value="true">
                            <Setter Property="Visibility" Value="Visible" TargetName="GlyphPanel"/>
                            <Setter Property="Visibility" Value="Collapsed" TargetName="Icon"/>
                        </Trigger>

                        <!-- Using the system colors for the Menu Highlight and IsEnabled-->
                        <Trigger Property="IsHighlighted" Value="true">
                            <Setter Property="Background" Value="{DynamicResource HighlightedBackgroundBrush}" TargetName="Border"/>
                            <Setter Property="Foreground" Value="{DynamicResource HighlightedText}"/>
                            <Setter Property="BorderBrush" Value="{DynamicResource NormalBorderBrush}" TargetName="Border"/>
                        </Trigger>
                        <Trigger Property="IsHighlighted" Value="false">
                            <Setter Property="Background" Value="{DynamicResource AppBackground}" TargetName="Border"/>
                            <Setter Property="Foreground" Value="{DynamicResource SolidMenuFontBrush}"/>
                            <Setter Property="BorderBrush" Value="{DynamicResource AppBackground}" TargetName="Border"/>
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Foreground" Value="LightGray"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>

...
<!-- The Popup is the body of the menu which expands down or across depending on the level of the item --> 
<Popup ...> 
   <Border x:Name="SubMenuBorder" ... Padding="0">...</Border>...</Popup>