title: UIImagePickerController crashes when using PhotoLibrary as source
body: <p>I'm using xcode 5.1 and tested the code both on ios7.1 and 7.0.2. The app crashes with UIImagePickerController in two scenarios on the device:</p>
  
  <p>1) when <code>allowsEditing</code> is set to YES, after I crop a picture and press "Choose", as soon as it goes back to my own view, the app crashes</p>
  
  <p>2) inside <code>UIImagePickerController</code>, when I go back from the photo list to the album list and I was at the bottom of the photo list, it crashes (no matter <code>allowsEditing</code> is YES or not). Note it does not crash if I scrolled the photo list up.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>- (IBAction)photoPickPressed:(id)sender {
  
      if ([self isPhotoLibraryAvailable]) {
  
          self.imagePicker = [[UIImagePickerController alloc] init];
          self.imagePicker.delegate = self;
          self.imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
          self.imagePicker.allowsEditing = YES;
          NSString *requiredMediaType = (__bridge NSString*)kUTTypeImage;
          self.imagePicker.mediaTypes = [[NSArray alloc] initWithObjects:requiredMediaType, nil];
          [self presentViewController:self.imagePicker animated:YES completion:nil];
      }
  }
  
  #pragma mark - image picker delegates
  - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
      [picker dismissViewControllerAnimated:YES completion:^(){
          NSLog(@"finished image picking");
      });
  }
  
  - (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
      [picker dismissViewControllerAnimated:YES completion:nil];
  }
  </code></pre>
  
  <p>The crash message is</p>
  
  <p><strong>* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*</strong> -[NSProxy doesNotRecognizeSelector:scrollViewDidScroll:] called!'</p>
  
  <p><strong>Note</strong>: it does <strong>NOT</strong> crash if I use camera even if I set <code>allowsEditing</code> to YES. Also it <strong>ONLY</strong> crashes on the real devices, not on the simulator.</p>
  
  <p>Just to clarify (maybe unrelated), originally I declared the imagePicker as</p>
  
  <pre><code>UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
  </code></pre>
  
  <p>, and it crashed. So I googled a lot, and a post says the controller might be recycled, and suggested to declare it in the class definition. So now I declared it in my class declartion:</p>
  
  <pre><code>@property (strong, nonatomic) UIImagePickerController *imagePicker;
  </code></pre>
  
  <p>Thanks in advance.</p>
  
  <p>Update: I tried to even put the invoke of imagePickerController to the root view of my app, and it still crashes with the same message. I shouldn't have any scrollable view loaded yet.</p>