 
   static let operationQueue: NSOperationQueue = {
     let queue = NSOperationQueue()
-    queue.maxConcurrentOperationCount = 3
+    queue.maxConcurrentOperationCount = 30
     return queue
   }()
 
   var imageID: Int64? {
     didSet {
+      cancelImageLoadingOperation()
+      image = nil
+
       if let imageID = imageID {
         let _operation = GetPostImageOperation(imageID: imageID)
         _operation.delegate = self

  }

  func getPostImageOperation(operation: GetPostImageOperation, didFinishWithImage image: UIImage) {
    self.image = image
  }

  func getPostImageOperation(operation: GetPostImageOperation, didFailWithError error: ErrorType) {

    operation?.cancel()
    operation?.delegate = nil
    operation = nil
    progressIndicator.progress = 0
  }

}
