title: UITapGestureRecognizer not responding on animated subview
body: <p>I have a simple program that creates a subview and animates it across the screen.</p>
  
  <p>As part of this program, I would like to add functionality when the subview is tapped.  I am using the following method to create the subview, add the UITapGestureRecognizer and then animate the subview:</p>
  
  <pre><code>int randomName = arc4random() % ([pieceNames count] - 1);
  int animationDuration = arc4random() %  5 + 5 ;
  NSString *randomPiece = [pieceNames objectAtIndex:randomName];
  
  float yStart = arc4random() % 650;
  float yEnd = arc4random() % 650;
  
  UIView *piece = [[PieceView alloc]initWithFrame:CGRectMake(100.0, yStart, 75.0, 75.0)];
  [piece setValue:randomPiece forKey:@"name"];
  
  UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc]initWithTarget:self
                                                                              action:@selector(handleTouch:)];
  [piece addGestureRecognizer:recognizer];
  
  [[self view] addSubview:piece];
  
  [UIView animateWithDuration:animationDuration
                        delay:0.0
                      options:UIViewAnimationOptionAllowUserInteraction
                   animations:^(void){
                       piece.center = CGPointMake(950.0, yEnd);
                   } completion:^(BOOL done){
                       [piece removeFromSuperview];
                   }];
  </code></pre>
  
  <p>Here is the code that handles the tap:</p>
  
  <pre><code>PieceView *pv = (PieceView *) recognizer.view;
  NSLog(@"%@ was tapped", pv.name);
  </code></pre>
  
  <p>What happens is when a PieceView is touched the program does not respond.  However, if I remove the animation block then the program responds to the tap.</p>
  
  <p>Why does the UITapGestureRecognizer fail to respond to PieceView when it is animated?</p>