title: UIAlertview delegate will crash when setting delegate to self
body: <p>I have this simple piece of code:</p>
  
  <pre><code>UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Contact" message:@"This contact does not exist yet" delegate:self cancelButtonTitle:@"Ok"  otherButtonTitles:@"Not now", nil];
  [alert show];
  </code></pre>
  
  <p>If I set delegate to 'nil', everything is fine. However, if I set delegate to 'self' and add either a clickedButtonAtIndex or didDismissWithButtonIndex delegate, the application crashes with EXC_BAD_ACCESS</p>