Deleting Entities

   Hello Dear; 
    I am starting my development with DevForce. I am getting well along with it but I have come accross ascenario I would like guidance from any person having experience with DevForce.

I have a form with controls bould to a BindingSource which i then bound BindableList of entities. I can Adding and Editing without problems. However when I try to Delete Items with my Binding Navigator they still appear on the form.

I use something like this 

(contractBindingSource.Current as Contract).Delete(); for a Contract which contains Facilities ( Entities in my System) and to delete a facility I call something like this (Using XtraGrid)

private void OnKeyDown(object sender, KeyEventArgs e)

{
if (e.KeyCode == Keys.Delete)

{
(facilitiesBindingSource.Current as ContractFacility).Delete();

}
}

Please can anybody help me with this.