title: app crashes when I try to call dismissViewController
body: <p>I have a view which I call my method:</p>
  
  <pre><code>    Twitter *tweet = [[Twitter alloc] initWithNibName:@"Twitter" bundle:nil];
  
  [self presentModalViewController:tweet animated:YES];
  </code></pre>
  
  <p>the viewcontroller is presented without any problem. Now when i try to call dismissviewcontroller in method of twitter view controller like :
          [self dismissModalViewControllerAnimated:NO];</p>
  
  <p>the app crashed ?</p>
  
  <p>Even though basic structure is right but Still app crashes ? Why is that so ?</p>