Why won't my inner control center in my ItemsControl?

<Window x:Class="Shell"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:cal="http://www.codeplex.com/CompositeWPF"
        xmlns:System="clr-namespace:System;assembly=mscorlib"
    Title="Referee" MaxWidth="800" MaxHeight="600" >
    <Window.Resources>
        <Style x:Key="GlassButton" TargetType="{x:Type Button}">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type Button}">
                        <Canvas x:Name="Button" Cursor="Hand">
                            <Rectangle x:Name="basecoat"
                            Height="30" Width="100"
                            StrokeThickness="0" 
                            Fill="Black" />
                            <Rectangle x:Name="glow"
                            Height="30" Width="100"
                            StrokeThickness="0" >
                                <Rectangle.Fill>
                                    <RadialGradientBrush Center="0.52,1.008" GradientOrigin="0.52,1.008" RadiusX="0.745" RadiusY="0.667">
                                        <GradientStop Color="#FF287178" Offset="0.188"/>
                                        <GradientStop Offset="1" Color="#00000000"/>
                                    </RadialGradientBrush>
                                </Rectangle.Fill>
                            </Rectangle>
                            <Rectangle x:Name="Glass" 
                            Height="30" Width="100"
                            StrokeThickness="0" Opacity="0.8" >
                                <Rectangle.Fill>
                                    <LinearGradientBrush EndPoint="0.5,0" StartPoint="0.5,1">
                                        <GradientStop Color="#00000000" Offset="0.358"/>
                                        <GradientStop Color="White" Offset="1"/>
                                        <GradientStop Color="#41414141" Offset="0.586"/>
                                        <GradientStop Color="#45454545" Offset="0.573"/>
                                    </LinearGradientBrush>
                                </Rectangle.Fill>
                            </Rectangle>
                            <ContentPresenter 
                        HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                        VerticalAlignment="{TemplateBinding VerticalContentAlignment}" 
                        SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" 
                        RecognizesAccessKey="True" />
                        </Canvas>
                        <ControlTemplate.Triggers>
                            <Trigger Property="IsFocused" Value="True"/>
                            <Trigger Property="IsDefaulted" Value="True"/>
                            <Trigger Property="IsMouseOver" Value="True"/>
                            <Trigger Property="IsPressed" Value="True"/>
                            <Trigger Property="IsEnabled" Value="False"/>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
        <Style x:Key="GlassItemsControl" TargetType="{x:Type ItemsControl}">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type ItemsControl}">
                        <Canvas>
                            <Rectangle x:Name="basecoat"
                                VerticalAlignment=开发者_C百科"Top"
                                Height="30" MinWidth="800"
                                StrokeThickness="0" 
                                Fill="Black"/>
                            <Rectangle x:Name="Glass" VerticalAlignment="Top" 
                                Height="30" MinWidth="800" 
                                StrokeThickness="0" Opacity="0.8">
                                <Rectangle.Fill>
                                    <LinearGradientBrush EndPoint="0.5,0" StartPoint="0.5,1">
                                        <GradientStop Color="#00000000" Offset="0.358"/>
                                        <GradientStop Color="White" Offset="1"/>
                                        <GradientStop Color="#41414141" Offset="0.586"/>
                                        <GradientStop Color="#45454545" Offset="0.573"/>
                                    </LinearGradientBrush>
                                </Rectangle.Fill>
                            </Rectangle>
                            <ScrollViewer 
                                HorizontalContentAlignment="Center" 
                                VerticalScrollBarVisibility="Hidden">
                                <ItemsPresenter/>
                            </ScrollViewer>
                        </Canvas>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </Window.Resources>
    <Grid MinHeight="480px" MinWidth="640px" Height="600" Width="800" >
        <Grid.ColumnDefinitions>
            <ColumnDefinition />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition  Height="130"/>
            <RowDefinition />
        </Grid.RowDefinitions>
        <ItemsControl x:Name="ToolBarRegion" Background="Black"
                       Grid.Row="0" />
        <ItemsControl x:Name="MainRegion" Background="Black" 
                       Grid.Row="1" />
        <ItemsControl x:Name="ButtonRegion" Height="35" Grid.Row="0" 
                      VerticalAlignment="Bottom"
                      Style="{StaticResource GlassItemsControl}"
                      HorizontalContentAlignment="Center">
            <Grid >
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="100"/>
                    <ColumnDefinition Width="100"/>
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition Height="30"/>
                </Grid.RowDefinitions>
                <Button Style="{StaticResource GlassButton}" 
            Grid.Column="0"
            Foreground="White" 
            Content="EDIT"  />
                <Button Style="{StaticResource GlassButton}"
            Grid.Column="1"
            Foreground="White" 
            Content="ADD OFFICE"/>
            </Grid>
        </ItemsControl>

    </Grid>
</Window>

I am using prism to do this, I just recreated the code so that I could post it here and you guys could tell me what I am missing. I am sure its something simple...Ive tried everything I can think of. I would imagine I am just missing something.

If you are asking why do the Buttons not center in the ItemsControl, then take a look at the GlassButton style defined in the Window.Resources. The GlassButton style has a ControlTemplate using a Canvas as the container. Canvas will set the X,Y coordinates of its children at 0,0. Change the Canvas to a Grid and your buttons will center as expected.