title: why is viewdidunload function not called when i click back button on navigation based app
body: <p>Hi I want to release my <code>fetchedResultsController</code>.</p>
  
  <p>I was wondering why is <code>viewdidunload</code> not called when i push back button on navigation based application.or i should release it somewhere else?</p>
  
  <p>thanks for help</p>