title: Objects in SpriteKit Game Stopped Colliding after iOS 7.1 update
body: <p>Objects in my spriteKit game stopped colliding after the iOS 7.1 update. This includes the bounds of the screen so the character just runs off screen. I'm using a bit mask to detect collisions and handling the collisions in the didBeginContact delegate method. I'll add the code for how I'm adding my SKNodes. Thanks in advance. </p>
  
  <pre><code>//main character 
  self.girl = [SKSpriteNode spriteNodeWithImageNamed:@"pixelgirl"];
  self.girl.position = CGPointMake(self.size.width / 2, self.size.height * 0.2);
  [self addChild:self.girl];        
  self.girl.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:self.girl.size.height / 4];
  self.girl.physicsBody.dynamic = YES;
  self.girl.physicsBody.affectedByGravity = NO;
  self.girl.physicsBody.mass = 0.02;
  self.girl.physicsBody.allowsRotation = NO;
  self.girl.physicsBody.categoryBitMask = girlCategory;
  self.girl.physicsBody.contactTestBitMask = tallTreeCategory | uglyTreeCategory | shortTreeCategory;
  
  //contact object 
  SKSpriteNode *pixelShort = [SKSpriteNode spriteNodeWithImageNamed:@"pixelshort"];
  pixelShort.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:pixelShort.size.width / 2]; //2
  pixelShort.physicsBody.dynamic = NO;
  pixelShort.physicsBody.categoryBitMask = uglyTreeCategory;
  
  - (void)didBeginContact:(SKPhysicsContact *)contact
  {
  
  __block BOOL isRotating;
  
  [self performSelector:@selector(moveDog) withObject:Nil afterDelay:.3];
  
  isRotating = NO;
  
  if (!isRotating) {
      SKAction* action0 = [SKAction scaleXTo:1.0 duration:0.05];
      SKAction* action1 = [SKAction scaleXTo:0.1 duration:0.05];
      SKAction* action2 = [SKAction scaleXTo:-0.1 duration:0.05];
      SKAction* action3 = [SKAction scaleXTo:-1.0 duration:0.05];
  
      SKAction* action = [SKAction sequence:@[action0,action1,action2, action3]];
  
      [self.girl runAction:action completion:^{
          isRotating = YES;
      }];
  
      }
  
  }
  </code></pre>