title: How to correctly removeFromSuperview?
body: <p>Apple says:</p>
  <blockquote>
  <p>removeFromSuperview Unlinks the
  receiver from its superview and its
  window, and removes it from the
  responder chain.</p>
  <ul>
  <li>(void)removeFromSuperview</li>
  </ul>
  <p>Never invoke this method while
  displaying.</p>
  </blockquote>
  <p>So, when I want to get rid of a view, I was used to just kick it off from it's superview. Why should I never invoke that while it's visible? So I must set it to hidden=YES before I do that?</p>