title: code crashes when sprite go to the position
body: <p>I use following code to show cloud randomly</p>
  
  <pre><code>- (void) cloudFly
  {
    int whichcloud = (arc4random() % 2) + 1;
    CCSprite *target = [CCSprite spriteWithImageNamed:[NSString stringWithFormat:@"cloud%d.png",whichcloud]];
    target.opacity = 0.3;
  
  int minY = target.contentSize.height / 2;
  int maxY = winSize.height - target.contentSize.height / 2;
  int rangeY = maxY - minY;
  int actualY = (arc4random() % rangeY) + minY;
  
  target.position = ccp(winSize.width + (target.contentSize.width/2), actualY);
  [self addChild:target];
  
  int minDuration = 1.0;
  int maxDuration = 3.0;
  int rangeDuration = maxDuration - minDuration;
  int actualDuration = (arc4random() % rangeDuration) + minDuration;
  
  // Create the actions
  id actionMove = [CCActionMoveTo actionWithDuration:actualDuration position:ccp(-target.contentSize.width / 2, actualY)];
  id actionMoveDone = [CCActionCallFunc actionWithTarget:self selector:@selector(cloudFinished:)];
  [target runAction:[CCActionSequence actions:actionMove, actionMoveDone, nil]];
  [_clouds addObject:target];
  }
  
  - (void)cloudFinished:(id)sender
  {
    CCSprite *sprite = (CCSprite *)sender;
    [sprite stopAllActions];
    [self removeChild:sprite cleanup:YES];
  }
  </code></pre>
  
  <p>but when the cloud flys to the position, this code will crash at line  </p>
  
  <pre><code>- (void)cloudFinished:(id)sender
  </code></pre>
  
  <p>I use cocos2d-iphone v3.x, I try to comment/remove all codes in </p>
  
  <pre><code>- (void)cloudFinished:(id)sender
  </code></pre>
  
  <p>but it still crash. BWT, does ccsprite remove tag?</p>