title: Custom MKAnnotation Image goes back to default when I attempt to drag
body: <p>I've got a bunch of MKAnnotations that don't need dragging.  I set this by <code>[pin setDraggable:NO]</code>.  I'm having an issue when I touch the annotation and (accidentally) drag off an annotation, it instantly looses it's custom image and changes back to the default red pin.  How do I prevent this from happening?</p>