IOS Swift Image rotated when loaded into UIImageView

In my app, I have a button with which I open the Gallery as below:

@IBAction func selectPhoto() {
    let photoPicker = UIImagePickerController()
    photoPicker.delegate = self
    photoPicker.sourceType = .PhotoLibrary
    self.presentViewController(photoPicker, animated: true, completion: nil)
}

I let the user select a photo and save it:

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
    photoImageView.image = info[UIImagePickerControllerOriginalImage] as? UIImage        
    let fileName:String = "logo.png"        
    let arrayPaths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as NSString        
    let pngFileName = arrayPaths.stringByAppendingPathComponent(fileName)                UIImagePNGRepresentation(photoImageView.image!)!.writeToFile(pngFileName, atomically:true)        
    imageSave.setObject(fileName, forKey: "pngFileName")        
    self.dismissViewControllerAnimated(false, completion: nil)
}

Then from View controller, the pictures saved is shown everytime the user gets to the scene using below code.

 override func viewDidLoad() {
    super.viewDidLoad()

    if imageSave.stringForKey("pngFileName") != nil
    {
        let path = NSSearchPathForDirectoriesInDomains(
            .DocumentDirectory, .UserDomainMask, true)[0] as NSString
        let fileName = NSUserDefaults.standardUserDefaults()
            .stringForKey("pngFileName")
        let imagePath = path.stringByAppendingPathComponent(fileName!)
        let image = UIImage(contentsOfFile: imagePath )            
        photoImageView.image = image

    }

Problem : When the image loads back onto the UIImageView, the orientation of the picture is sometimes rotated right by 90 degrees, sometimes rotated left by 90 degrees or sometimes shown as it was saved.

Please let me know what I am doing wrong here. Any help would be appreciated. Thanks