title: ios 6 MapKit annotation rotation
body: <p>Our app has a rotating map view which aligns with the compass heading. We counter-rotate the annotations so that their callouts remain horizontal for reading. This works fine on iOS5 devices but is broken on iOS6 (problem seen with same binary as used on iOS5 device and with binary built with iOS6 SDK). The annotations initially rotate to the correct horizontal position and then a short time later revert to the un-corrected rotation. We cannot see any events that are causing this. This is the code snippet we are using in - (MKAnnotationView *)mapView:(MKMapView *)theMapView viewForAnnotation:(id )annotation</p>
  
  <pre><code>CATransform3D transformZ = CATransform3DIdentity;
  transformZ = CATransform3DRotate(transformZ, _rotationZ, 0, 0, 1);
  annotation.myView.layer.transform = transformZ;
  </code></pre>
  
  <p>Anyone else seen this and anyone got any suggestions on how to fix it on iOS6?</p>