EKEventEditViewController doesn't show recent events.

I integrated EKEventEditViewController on my calendar app. When I type some text on the title field, it is supposed to show matched events with title. If you use iCal and type title, you can see the search result below title field. I believe I am using the same class for creating an event, EKEventEditViewController. I am wondering why my EKEventEditViewController doesn't show searching list.