I am having a problem with the lower bound grid line not showing. Maybe this is the way it should be, but I am not sure. I was hoping someone could help me out with this. I have a PrimaryX axis defined as follows:

<igCA:Axis AxisType="PrimaryX" x:Name="PrimaryXAxis" 

       RangeFromZero="True"
       AutoRange="False" Unit="1" Minimum="0" 
       Maximum="{Binding TotalHoursOnChart}">
<igCA:Axis.MajorGridline>
    <igCA:Mark Visible="True" Unit="0.5" StrokeThickness="0.75" />
</igCA:Axis.MajorGridline>
<igCA:Axis.MajorTickMark>
    <igCA:Mark Visible="False"/>
</igCA:Axis.MajorTickMark>
<igCA:Axis.MinorGridline>
    <igCA:Mark Visible="True" Unit="1" StrokeThickness="2" 

        Stroke="{Binding ChartBackground, Mode=OneWay}" /> 
</igCA:Axis.MinorGridline>
<igCA:Axis.MinorTickMark>
    <igCA:Mark Visible="True" />
</igCA:Axis.MinorTickMark>
</igCA:Axis>

What I see on the chart is this: