title: iPhone App Crashing during navigation
body: <p>I have a tough problem (tough for me since I'm a newb.).  I have a table view app that I'm working on.  It starts with a table and you navigate down to a view controller.  In that view controller I'm using some sample code hooked into a button that will add a contact to the iPhone address book.</p>
  
  <p>My problem is when the user navigates back to the table of data, the app crashes.  Is there any advice someone can provide?  Or, maybe someone I could send me code for review?</p>
  
  <p>Update*</p>
  
  <p>Here's the information from the console.</p>
  
  <pre><code>[Session started at 2010-07-20 22:51:46 -0500.]
  2010-07-20 22:51:49.621 Infinite Possibilities[5882:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSPlaceholderString initWithString:]: nil argument'
  *** Call stack at first throw:
  (
   0   CoreFoundation                      0x025ff919 __exceptionPreprocess + 185
   1   libobjc.A.dylib                     0x0274d5de objc_exception_throw + 47
   2   CoreFoundation                      0x025b8078 +[NSException raise:format:arguments:] + 136
   3   CoreFoundation                      0x025b7fea +[NSException raise:format:] + 58
   4   Foundation                          0x0006869c -[NSPlaceholderString initWithString:] + 105
   5   Infinite Possibilities              0x00003b90 -[RootViewController tableView:didSelectRowAtIndexPath:] + 3405
   6   UIKit                               0x0034c718 -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] + 1140
   7   UIKit                               0x00342ffe -[UITableView _userSelectRowAtIndexPath:] + 219
   8   Foundation                          0x00059cea __NSFireDelayedPerform + 441
   9   CoreFoundation                      0x025e0d43 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 19
   10  CoreFoundation                      0x025e2384 __CFRunLoopDoTimer + 1364
   11  CoreFoundation                      0x0253ed09 __CFRunLoopRun + 1817
   12  CoreFoundation                      0x0253e280 CFRunLoopRunSpecific + 208
   13  CoreFoundation                      0x0253e1a1 CFRunLoopRunInMode + 97
   14  GraphicsServices                    0x02e642c8 GSEventRunModal + 217
   15  GraphicsServices                    0x02e6438d GSEventRun + 115
   16  UIKit                               0x002e8b58 UIApplicationMain + 1160
   17  Infinite Possibilities              0x00002834 main + 102
   18  Infinite Possibilities              0x000027c5 start + 53
  )
  terminate called after throwing an instance of 'NSException'
  </code></pre>