Here's what I'm calling unexpected behaviour:

A date cell is initially loaded from the CLR source, using databinding, with for examplle: 8/2/2012.  I select the cell and no matter what I key in, 6/1/2012 for example, when focus moves away from the cell the value reverts back to its original value, 8/2/2012 for example.  However, if I use the drop down calendar, DatePicker, and select a date, the selected date is displayed and also remains when focus moves away from the cell.

The application has other XamGrid's with DateColumns that work as I expect.

I'd appreciate any suggestions as to why this is happening and ways to troubleshoot it further.  Here is the Xaml (Snippet):

<ig:XamGrid Grid.Row="1" HorizontalAlignment="Stretch" Margin="0,0,0,0" Name="propertiesGrid" VerticalAlignment="Stretch" AutoGenerateColumns="False" ItemsSource="{Binding}" HeaderRowHeight="23" >
    <ig:XamGrid.EditingSettings>
         <ig:EditingSettings AllowEditing="Cell" IsMouseActionEditingEnabled="SingleClick" />
    </ig:XamGrid.EditingSettings>
    <ig:XamGrid.Columns>
        <ig:DateColumn Key="Data.BeginDate" HeaderText="Begin Date" />
        <ig:DateColumn Key="Data.EndDate" HeaderText="End Date" />
    </ig:XamGrid.Columns>
</ig:XamGrid>