title: Admob GADBannerView.m bool _WebTryThreadLock(bool) iOS iPhone crash
body: <p>I running the app on iPhone 3.1.3 (first gen iPhone) with admob sdk.  Thought not all the time, I started to get this error lately, which I never seen before.</p>
  
  <pre><code>&lt;Warning&gt;: bool _WebTryThreadLock(bool), 0x3c3840: Tried to obtain the web lock from a thread other than the main thread or the web thread. This may be a result of calling to UIKit from a secondary thread. Crashing now...
  </code></pre>
  
  <p>and then when I trace the error down in the log file,  I see</p>
  
  <pre><code>Thread 6 Crashed:
  0   WebCore                         0x00084380 _WebTryThreadLock(bool) + 288
  1   WebCore                         0x00084ac0 _WebThreadAutoLock() + 52
  2   UIKit                           0x0022061c -[UIWebView dealloc] + 128
  3   CoreFoundation                  0x0003963a -[NSObject release] + 28
  4   UIKit                           0x0000ab2c -[UIView(Hierarchy) removeFromSuperview] + 592
  5   UIKit                           0x0005ca1c -[UIView dealloc] + 232
  6   My iPhone App                       0x0008d4e0 0x1000 + 574688
  7   CoreFoundation                  0x0003963a -[NSObject release] + 28
  8   UIKit                           0x0000ab2c -[UIView(Hierarchy) removeFromSuperview] + 592
  9   UIKit                           0x0005ca1c -[UIView dealloc] + 232
  10  CoreFoundation                  0x0003963a -[NSObject release] + 28
  11  UIKit                           0x000cad5c -[UIViewController dealloc] + 188
  12  My iPhone App                       0x00015e60 0x1000 + 85600
  13  My iPhone App                       0x000135c4 0x1000 + 75204
  </code></pre>
  
  <p>and traced it down even further and got,</p>
  
  <pre><code>-[GADBannerView dealloc] (in My iPhone App) (GADBannerView.m:111)
  
  -[myViewController dealloc] (in My iPhone App) (myViewController.m:378)
  
  -[mySubViewController dealloc] (in My iPhone App) (mySubViewController.m:64)
  </code></pre>
  
  <p>I have no idea what's going on.  Is there something I can do to prevent the crash or is this something admob has to fix?</p>
  
  <p>Any help is apprecated</p>