iOS Problem in updating currentlocation annotation

[roopeshsoni]

I am trying to track my current location. For this I have set Mapviews "showsUserLocation" to YES . Like self.mapView.showsUserLocation = YES;

But my current location annotation is not updated when I move to a different location. Can any one suggest what could be the reason

For this default annotation. I am using a customview

- (void)viewDidLoad {
...	
	self.mapView.showsUserLocation = YES;
...
}

- (MKAnnotationView *)mapView:(MKMapView *)mapView 
            viewForAnnotation:(id <MKAnnotation>)annotation
{
 // my MKAnnotationView 
// return myMKAnnotationView
}

According to documents it says Setting showsUserLocation property to YES causes the map view to use the Core Location framework to find the current location. As long as this property is YES, the map view continues to track the user’s location and update it periodically.
Please let me know if some one faced the same issue