MKPinAnnotationView custom Image is replaced by pin with animating drop

Question

I'm displaying user avatar images on a MapView. The avatars appear to be working if they are rendered without animation, however I'd like to animate their drop. If I set pinView.animatesDrop to true, then I lose the avatar and it is replaced by the pin. How can I animate the drop of my avatar without using the pin?

Here is my viewForAnnotation method I'm using:

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {
    if ([annotation isKindOfClass:[MKUserLocation class]])
        return nil;

    MKPinAnnotationView* pinView = (MKPinAnnotationView*)[self.mapView dequeueReusableAnnotationViewWithIdentifier:@"MyAnnotation"];

    if (!pinView) {
        pinView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"CustomPinAnnotation"];
    }
    else
        pinView.annotation = annotation;

    //If I set this to true, my image is replaced by the pin
    //pinView.animatesDrop = true;

    //I'm using SDWebImage
    [pinView setImageWithURL:[NSURL URLWithString:@"/pathtosomeavatar.png"] placeholderImage:[UIImage imageNamed:@"placeholder.png"]];

    //Adding a nice drop shadow here
    pinView.layer.shadowColor = [UIColor blackColor].CGColor;
    pinView.layer.shadowOffset = CGSizeMake(0, 1);
    pinView.layer.shadowOpacity = 0.5;
    pinView.layer.shadowRadius = 3.0;

    return pinView;
}