title: MapView in iOS6 crashes when zooming map
body: <p>I'm trying to span a map to the center of two coordinates. It worked fine on previous versions of iOS, but now suddenly, I get this error message: </p>
  
  <pre><code>*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Invalid Region &lt;center:nan, nan span:nan, nan&gt;' 
  </code></pre>
  
  <p>Any ideas on what's wrong? </p>
  
  <pre><code>        CLLocationCoordinate2D savedCoordinate;
          savedCoordinate.latitude = [userDef doubleForKey:@"savedCoordinate-latitude"];
          savedCoordinate.longitude = [userDef doubleForKey:@"savedCoordinate-longitude"];
  
          savedPosition = savedCoordinate;
  
          CLLocationDistance visibleDistance = 100;
          MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(savedCoordinate, visibleDistance, visibleDistance);
          MKCoordinateRegion adjustedRegion = [mapView regionThatFits:region];
          [mapView setRegion:adjustedRegion animated:NO];
  </code></pre>