IsExpandable Property not retaining programatic settings

[Ray]

I can not get the row.IsExpandable property to keep it's setting after _RowLoaded event is done firing.  This is the last event that is fired before rendering the screen and handing control over to the user.  I am setting the IsExpandable property to either true or false in the _RowLoaded event.  Even though I am setting the IsExpandable property to false, the toggle button is still visible.  I need it to be collapsed 95% of the time.  Here is my RowLoaded method:

private void fleetGrid_RowLoaded(object sender, RowLoadedEventArgs e)
 {
       var row = e.Row as GridViewRow;

       if (row != null)
       {
              Record recItem = e.Row.Item as Record;
              row.IsExpandable = recItem.RequiredFields.ShowToggleOnGrid;
       }

}

I am populating the columns in this RadGridView dynamically, and I am using a GridViewToggleRowDetailsColumn along with GridViewDataColumns for the column types.  I only want this toggle button to show if certain properties of the row meet certain conditions, which is what the ShowToggleOnGrid was created for.  I have tried several of the online solutions -provided in the forums, but I can not get the toggle visibility I am looking for.  Any help on this issue would be greatly appreciated.  

[Ray]

This is the work around that I'm using to get the GridViewToggleColumn behavior that I am looking for:

private void fleetGrid_RowLoaded(object sender, RowLoadedEventArgs e)
        {
            var row = e.Row as GridViewRow;

            if (row != null)
            {
                Record recRow = row.Item as Record;
                GridViewCell gvCell = row.Cells[0] as GridViewCell;

                if (recRow.RequiredFields.ShowToggleOnGrid)
                {
                    gvCell.Visibility = Visibility.Visible;
                }
                else
                {
                    gvCell.Visibility = Visibility.Collapsed;
                }

            }

        }