title: Why UIRefreshControl jumping?
body: <p>I try to use the UIRefreshControl with swift 1.2 and works fine except the UI. It is jumping and I dont know why.
  Here is what I am doing:</p>
  
  <pre><code>class ViewController: UIViewController {
  
       var refreshControl:UIRefreshControl!
  
      @IBOutlet weak var tableView: UITableView!
      override func viewDidLoad() {
          super.viewDidLoad()
  
          self.refreshControl = UIRefreshControl()
          self.refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
          self.refreshControl.addTarget(self, action: "refresh:", forControlEvents: UIControlEvents.ValueChanged)
          self.tableView.addSubview(refreshControl)
      }
  
      func refresh(sender:AnyObject) {
          // Code to refresh table view
      }
  
  }
  </code></pre>
  
  <p>And you can download my poc project from here:
  <a href="https://www.dropbox.com/s/5rf67cp2dx80xnl/UIRefreshControlPOC.zip?dl=0" rel="noreferrer">POC project</a></p>
  
  <p>While you pull down the tableView, suddenly jump a little bit down. Has anybody any idea why?</p>
  
  <p>If I use with UITableViewController, It works fine but I dont want to use this UI object. I would like to use a simple UITableView in a UIViewController.</p>