title: Can presentModalViewController work at startup?
body: <p>I'd like to use a modal UITableView at startup to ask users for password, etc. if they are not already configured.  However, the command to call the uitableview doesn't seem to work inside viewDidLoad.</p>
  
  <p>startup code:</p>
  
  <pre><code>- (void)viewDidLoad {
    rootViewController = [[SettingsController alloc] 
      initWithStyle:UITableViewStyleGrouped];
    navigationController = [[UINavigationController alloc]     
      initWithRootViewController:rootViewController];
  
    // place where code doesn't work
    //[self presentModalViewController:navigationController animated:YES];
  }
  </code></pre>
  
  <p>However, the same code works fine when called later by a button:</p>
  
  <pre><code>- (IBAction)settingsPressed:(id)sender{
      [self presentModalViewController:navigationController animated:YES];
  }
  </code></pre>
  
  <p>Related question: how do I sense (at the upper level) when the UITableView has used the command to quit?</p>
  
  <pre><code>[self.parentViewController dismissModalViewControllerAnimated:YES];
  </code></pre>