title: ios UIBarButtonItem with UIBarButtonSystemItemCompose showing red button
body: <p>I am trying to add a UIBarButtonItem with the style of UIBarButtonSystemItemCompose. According to the apple docs it should display a compose icon that consists of a square outline. When I use the following code it just displays a red button. Does the icon only work if the uibarbuttonitem if placed inside of a UIToolBar and not a navigation bar.</p>
  
  <pre><code>self.navigationItem.rightBarButtonItem = [[[UIBarButtonItem alloc]
                                            initWithTitle:nil
                                            style:UIBarButtonSystemItemCompose
                                            target:self
                                            action:@selector(tweetPressed:)] autorelease];
  </code></pre>