title: Facebook iOS SDK 3.1 crashes on subsequent call to FBSession openWithBehavior
body: <p>If we call openWithBehavior after a call to closeAndClearTokenInformation, it causes EXC_BAD_ACCESS. Regardless of whether it is using the native iOS built-in dialog or one of the fast-switching ones. </p>
  
  <p>Our code to login to FB, first time through works:</p>
  
  <pre><code>if (![FBSession activeSession]) {
      #ifdef FREE_APP
          NSString* suffix = @"free";
      #else
          NSString* suffix = @"paid";
      #endif
      FBSession *session = [[[FBSession alloc] initWithAppID:@"111111111111111"
                              permissions:permissions
                          urlSchemeSuffix:suffix
                       tokenCacheStrategy:nil] autorelease];
      [FBSession setActiveSession:session];
  } 
  else if ([FBSession activeSession].isOpen)
      [[FBSession activeSession] close];
  
  [[FBSession activeSession] openWithBehavior:FBSessionLoginBehaviorUseSystemAccountIfPresent
                completionHandler:^(FBSession *session, FBSessionState state, NSError *error) {
                                       [self sessionStateChanged:session state:state error:error];
                                   }];
  </code></pre>
  
  <p>Our code to logout, after which the code above fails after openWithBehavior:</p>
  
  <pre><code>[[FBSession activeSession] closeAndClearTokenInformation];
  </code></pre>
  
  <p>I was initially using openActiveSessionWithReadPermissions instead of openWithBehavior, as prescribed in the 3.1 docs, which does not crash but the app switching back from FB app/Safari did not work.  Perhaps because of the need to have a suffix? If it would be easiest to fix the app switching and go back to that, please advise.  </p>
  
  <p>Thanks.</p>