I'm using following code to programmatically navigate to another ViewController. It works fine, but it some how hides the `navigation bar`. **How do I fix this?** (the navigation bar is created by embeding the `ViewController` in the `navigation controller` if that matters.)

```
let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)

let nextViewController = storyBoard.instantiateViewControllerWithIdentifier("nextView") as NextViewController
self.presentViewController(nextViewController, animated:true, completion:nil)

```