title: XIB file disappeared but application still works
body: <p>I'm using Xcode 4.0.2 and I opened up one of my projects today to find that a .xib file was missing (the .xib that the MainWindow loads). I can't see it in the Finder and it doesn't appear at all in the Xcode window, yet my application still works as if it's there.</p>
  
  <p>Anyone have any idea what might have happened here?</p>