title: UINavigationController back button action problem
body: <p>I have an UINavigationController and the first view is an UIView. I've setup two buttons and each one pushes another view , both UITableViewControllers.
  The first buttons works just fine. The problem is: when I'm in the second TableViewController and I tap on the back button it tries to push the view again and only the second time it goes back to the Main View.
  I also have an UITabBarController setup and I noticed that if I am in my first tab(the Main View with the two buttons pushing the two tableviews and precisely in the second view ) and i tap on another tab then tap back on the first - it shows me the content of my first UITableViewController and when I tap back it shows the second UITableViewController(that is supposed to be displayed) and only the second time i tap it goes to the Main View.</p>
  
  <p>I don't know if it's understandable what I just said, here is also the code for the back button and the action for it:</p>
  
  <pre><code>- (void)viewDidLoad {
      [super viewDidLoad];
      UIButton *back= [UIButton buttonWithType:UIButtonTypeCustom];  
      UIImage *backImage = [[UIImage imageNamed:@"backb.png"]  
                            stretchableImageWithLeftCapWidth:10 topCapHeight:10];  
      [back setBackgroundImage:backImage forState:UIControlStateNormal];  
      [back addTarget:self action:@selector(cancel:)  
     forControlEvents:UIControlEventTouchUpInside];  
      back.frame = CGRectMake(0, 0, 37, 26);  
      UIBarButtonItem *cancelButton = [[[UIBarButtonItem alloc]  
                                        initWithCustomView:back] autorelease];  
      self.navigationItem.leftBarButtonItem = cancelButton;
  }
  
  
  -(IBAction)cancel:(id)sender{  
      [self.navigationController popViewControllerAnimated:YES];  
  }
  </code></pre>
  
  <p>The back button in the first UITableViewController is setup the same  and works just fine...what could be the problem?</p>
  
  <p>I've just added another UITableViewController and obviously now when I'm in the third view and I try to go back to the Main View it loads the view two times and the first UITableViewController before it goes back...</p>