title: iOS navigation title doesn't show on subpage
body: <p>I have an app tab based with a navigation controller,</p>
  
  <p>the title in the navigation bar shows fine in the root page for the tab,</p>
  
  <p>but when I push another view controller, on top, I cannot set the title for this view</p>
  
  <p>this is the code I use for the root page and the pushed page,</p>
  
  <pre><code>- (void)viewDidLoad
  {
      [super viewDidLoad];    
  UILabel *lava = [[[UILabel alloc] initWithFrame:CGRectMake(0, 0, 320, 44)]autorelease];
      lava.backgroundColor = [UIColor clearColor];
  lava.text = @"About us"; 
  
  lava.textAlignment = UITextAlignmentCenter ;
  lava.textColor = [UIColor whiteColor];
  lava.font = [UIFont fontWithName:@"DroidSans-Bold" size:(46)];
  lava.shadowColor = [UIColor blackColor];
  lava.shadowOffset = CGSizeMake(2, 3);
  self.navigationItem.titleView = lava;
  
   }
  </code></pre>
  
  <p>so, what is missing to set my title on the nav bar?</p>
  
  <p>thanks!</p>