I am defining the following CellValuePresenter style

<Style x:Key="CellColorStyle" TargetType="{x:Type igWPF:CellValuePresenter}">
<!-- Template combines icon set by a separate converter and Text into the same cell -->

<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type igWPF:CellValuePresenter}">
<StackPanel Orientation="Horizontal">
<Image Source="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Value, Converter={StaticResource StatusIconConverter}}" Width="16" Height="16" Margin="5" />
<TextBlock VerticalAlignment="Center" HorizontalAlignment="Left" Text="{Binding RelativeSource={RelativeSource AncestorType={x:Type igWPF:CellValuePresenter}}, Path=Value}"/>
</StackPanel>
</ControlTemplate>
</Setter.Value>
</Setter>

<Setter Property="BorderBrush" Value="Black"/>
<Setter Property="BorderThickness" Value="2,0,2,0"/>
</Style>

Style is set for one of the Fields in the grid. For whatever reason the column separators between this cells in that column and the adjacent column have gone missing. I attempted to explicitely add the BorderBrush and Borderthickness but these have not helped. Any idea how to restore the separators? Thanks.