UltraGrid Drill Down


I have been trying to get an ultragrid to drill down (hierarchical) on a dataset without much success.
I have a single dataset in which I have two datatables. A header and a detail file in which I have set up the primary key and have also set up a data relationship between the two tables and this looks like all you need to do as per the infragistics site. Has anyone else had issues trying to do this or suggest a possible solution. Is there anything else I need to do in order to get this to work?

Any help would be appreciated.