Hello jon byron,
Thank you for directing us to a concrete scenario. It seems that the GridDropDownColumn cannot handle its data binding if RadGrid's data source does not have items and the dropdown column has a ColumnEditorID
specified. The above condition makes the dropdown column inherit properties from the column editor specified, but breaks the binding logic if RadGrid does not have data items.
This issue is logged in our bug tracking system and is to be fixed as soon as possible. For now, please, refrain from using declarative column editors with the GridDropDownColumn. The demo example you refer to can be fixed simply removing the ColumnEditorID property from the markup of the dropdown column.
the Telerik team