title: view seems to reload itself
body: <p>If I stop using my app for a long time then go back to it, it seems like the <code>viewDidLoad</code> method is being called again, even though I <strong>never</strong> "exited" the app (by pressing the home key twice and tapping the X) nor did I reboot the iPhone.  If I just go to the home screen and then open the app again after a short time this does not happen.  What is going on?</p>