title: App Crashes when NavigationController is popped!
body: <p>Below is what I copy/pasted from the Crash Log sent by the client. I am unable to understand what does that mean :s</p>
  
  <p>Apparently it looks like the app crashed when navigating back to a previous screen (and that's what client has reported). What is UIWebDocumentView here?</p>
  
  <p>I need to resolve the crash but I'm stuck here so any help is highly appreciated.</p>
  
  <p>P.S. I'm using iphone sdk 3.0.</p>
  
  <pre><code>Date/Time:       2009-09-29 18:16:28.458 -0400
  OS Version:      iPhone OS 3.0 (7A341)
  Report Version:  104
  
  Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
  Exception Codes: KERN_INVALID_ADDRESS at 0xbbadbeef
  Crashed Thread:  4
  
      Thread 4 Crashed:
  
          0   WebCore                         0x3588dd74 __ZL17_WebTryThreadLockb + 288
          1   WebCore                         0x3588e4c0 __ZL18_WebThreadAutoLockv + 52
          2   UIKit                           0x30aea484 -[UIWebDocumentView _responderForBecomeFirstResponder] + 8
          3   UIKit                           0x30978b34 -[UINavigationTransitionView transition:fromView:toView:] + 200
          4   UIKit                           0x30978a54 -[UINavigationTransitionView transition:toView:] + 24
          5   UIKit                           0x30974470 -[UINavigationController _startTransition:fromViewController:toViewController:] + 1604
          6   UIKit                           0x30973d90 -[UINavigationController _startDeferredTransitionIfNeeded] + 256
          7   UIKit                           0x309a7468 -[UINavigationController _popViewControllerWithTransition:allowPoppingLast:] + 400
          8   UIKit                           0x309a72c8 -[UINavigationController popViewControllerAnimated:] + 32
          9   Snocell                         0x0002ae00 0x1000 + 171520
          10  Foundation                      0x30554062 -[NSThread main] + 42
          11  Foundation                      0x305023f2 __NSThread__main__ + 852
          12  libSystem.B.dylib               0x31d705a0 _pthread_body + 20
  </code></pre>