title: XIB files becoming blank - using iPhone sdk 4
body: <p>I just updated to iPhone SDK4. The problem I am facing is - I was writing an app in iPhone sdk 3.0 just open that project in xcode 3.2.3 made some changes in xib file, now when i run this project in simulator the user interface (xib) appearing blank (with black color).</p>
  
  <p>Any idea why this is happening...?</p>
  
  <p>Thanks
  Saurabh</p>