Silverlight 3;

I have a ValidationSummary in the top row of my grid. When the ValidationSummary appears, it pushes my button row (row 3) off the bottom of the displayable screen.

<Grid HorizontalAlignment="Stretch"
          VerticalAlignment="Stretch">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="36" />
        </Grid.RowDefinitions>

        <di:ValidationSummary Grid.Row="0" />

        <Grid x:Name="gridOuterContentHolder"
              Grid.Row="1">
            <Grid.RowDefinitions>
                <RowDefinition Height="0.68*" />
                <RowDefinition Height="5" />
                <RowDefinition Height="0.32*" />
            </Grid.RowDefinitions>
<!-- elements removed for brevity -->

        </Grid>

        <StackPanel x:Name="stack"
                    Grid.Row="2"
                    Orientation="Horizontal"
                    HorizontalAlignment="Right">
            <Button Content="Delete"
                    x:Name="btnDelete"
                    Height="20"
                    Width="75" />

        </StackPanel>
    </Grid>

I'm a code monkey not a pixel pusher and can't figure out which combination of Stretch's, Auto's and *'s I need. Any pushers out there that can help??

Thanks, Mark