title: UIView's edge flickers at the end of an animation
body: <p>My main <code>UIViewController</code> has a sub <code>UIView</code> named <code>viewContainer</code>. It has a couple of <code>UIImageView</code>s, <code>UIButton</code>s and <code>UIView</code>s added to it. In my <code>viewDidLoad</code> method I've applied the following to <code>viewContainer</code>:</p>
  
  <pre><code>self.viewContainer.layer.shadowColor = [UIColor blackColor].CGColor;
  self.viewContainer.layer.shadowOffset = CGSizeMake(0, 0);
  self.viewContainer.layer.shadowOpacity = 1.0;
  self.viewContainer.layer.shadowRadius = 10.0;
  self.viewContainer.layer.shadowPath = [UIBezierPath bezierPathWithRect:self.viewContainer.layer.bounds].CGPath;
  
  self.viewContainer.backgroundColor = [UIColor blackColor];
  self.viewContainer.opaque = YES;
  </code></pre>
  
  <p>When a user presses a button inside the <code>viewContainer</code>, I perform the following translation:</p>
  
  <pre><code>[UIView animateWithDuration:0.3
                   animations:^{
                           [self.viewContainer setCenter: CGPointApplyAffineTransform(self.viewContainer.center, CGAffineTransformConcat(self.viewContainer.transform, CGAffineTransformMakeTranslation(60, 0)))];
                   }
                   completion:nil];
  </code></pre>
  
  <p>My problem is that at the end of the animation, the edge of the view flickers for a fraction of a second (a white vertical line). I've tried setting the frame instead of a transform but still the same result. I'm attempting to do a sort of slide to reveal options thing, which works but flickers on completion.</p>
  
  <p>Any ideas?</p>