Binding the form to an MVVM which exposes a SearchCommand and 2 DateTime? fields.

The view contains 2 DatePicker controls, a Search Button and a Hierarchical Grid to display the results.  Upon clicking search the property that the Grid is bound to changes and fires propertychanged event.  The grid successfully updates with my lazy loading children/grandchildren, but the summary remains the same.

Any ideas or suggestions?

Chr15t1an