ListControl SelectedValue not working

I am experiencing a problem that seems VERY related to this one.  I originally discovered this while chasing down binding and datasource theories on this problem.  I have now isolated it to the inability to write to the SelectedValue for the radDDL.

        private void radGridView1_RowsChanged(object sender, Telerik.WinControls.UI.GridViewCollectionChangedEventArgs e)
        {
            var tsd = (t_Estimates)this.t_EstimatesBindingSource.Current;
            if (tsd != null) { ServiceTyperadDropDownList.SelectedValue = tsd.ServiceType.Value; }
        }

I have confirmed, that when the IF Conditional is executed, tsd.ServiceType.Value = 5.  After exiting, ServiceTyperadDropDownList.SelectedValue = null.

I have several other radDDLs on the same form that work fine.  It is only this one.  I compared them, and could not identify any differences.  Additionally, this appears to only be a problem with the 1st record in the t_EstimatesBindingSource Entity dataset.

Please advise.

-Scott