title: MapKit repsondsToSelector for setUserTrackingMode in IOS 4.3.3
body: <p>I have the following code</p>
  
  <pre><code>BOOL ios5 = [mapview respondsToSelector:@selector(setUserTrackingMode:animated:)];
  if(ios5)
  {
      if(compass &amp;&amp; tracking)
          [mapview setUserTrackingMode:MKUserTrackingModeFollowWithHeading animated:YES];
      else if (tracking)
          [mapview setUserTrackingMode:MKUserTrackingModeFollow animated:YES];
      else
          [mapview setUserTrackingMode:MKUserTrackingModeNone animated:YES];
  }
  else
  {
      // Do it the version 4.0 way
  }
  </code></pre>
  
  <p>It works as expected depending on whether I have the compass or tracking flags on and tracks the user location in iOS 5.</p>
  
  <p>However, it also works in version 4.3.3 which is the other device I'm testing on. It seems to respond to the selector and actually behaves as it does in iOS 5.</p>
  
  <p>Is this because the functionality was in iOS 4 but not made public and I run the risk of the app being rejected for that reason?</p>
  
  <p>Can anyone shed some light on this?
  thanks
  Donie</p>