CLLocationManager delegate method is not called in iOS4

I am currently working in Map feature and i get the current location and displayed. Now i am running my apps in iOS4.CLLocationManger delegate method is not calling, when running the apps in iOS4. But i could run my application in older version of Xcode 3.1.4. it works fine and delegat开发者_如何学Ce method also called properly. So how can i call the CLLocationManger delegate method in iOS4? Its very weird to me.

- (void)locationManager: (CLLocationManager *)manager didUpdateToLocation: (CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{   
      NSLog(@"inside didUpdateToLocation");

      MKCoordinateRegion region1;

      region1.center = newLocation.coordinate;

      region1.span.latitudeDelta = 0.001;

      region1.span.longitudeDelta = 0.001;

      mapview.mapType = MKMapTypeStandard;

      [mapview setRegion:region1 animated:TRUE];

      [locationManager stopUpdatingLocation];

}

Please help me out.

Thanks.

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Turned On the Airport and seems to work OK now. Very Weird....

This was also reported before for Xcode 3.1.3. but since now I always used 3.1.2 on Simulator. When I updated to iOS4 this issue appeared. Very annoying....