title: network activity indicator is not shown on iPhone (iOS 5)
body: <p>just to test it I enabled the activity indicator of the status bar as follows:</p>
  
  <pre><code>- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
  {
      [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible: TRUE]; 
  
      //...
  }
  </code></pre>
  
  <p>I never disable the indicator so it should always be visible, but it isn't. It is visible in the iPhone Simulator but not on the device. Why?</p>