title: UIView.hidden doesn't work immediately
body: <p>I have a UIViewController with a UITableView and UIView (see blow). When I call <code>hiddenLoadingView</code> at somewhere, the UIView is still showing, then dismiss after 10-20 seconds, why?</p>
  
  <pre><code>- (void)viewDidLoad {
      ....
      self.tableView = [[[UITableView alloc] init] autorelease];
      [self.view addSubview:self.tableView];
  
      self.loadingView = [[[UIView alloc] init] autorelease];
      [self.view addSubview:self.loadingView];
  }
  
  - (void)hiddenLoadingView {
      NSLog(@"%@", [NSNumber numberWithBool:self.loadingView.hidden]);
      [self.loadingView setHidden:YES];
      NSLog(@"%@", [NSNumber numberWithBool:self.loadingView.hidden]);
  }
  </code></pre>