title: iCloud Key-Value-Store Synchronization issues (NSUbiquitousKeyValueStoreDidChangeExternallyNotification not called)
body: <p>i am writing a small universal game for iOS. 
  the highscore will be synched accross devices through an iCloud Key/Value store.</p>
  
  <p>getting the newest score:</p>
  
  <pre><code>func retrieveHighestScore() -&gt; Int64 {
          let iCloudScore: Int64 = NSUbiquitousKeyValueStore.defaultStore().longLongForKey(KeyValueKeyClassification.KeyHighscore.toRaw())
          let localScore: Int64 = Int64(NSUserDefaults.standardUserDefaults().integerForKey(KeyValueKeyClassification.KeyHighscore.toRaw()))
          var result: Int64 = 0
  
          if localScore &gt; iCloudScore {
              storeNewHighscore(localScore)
              result = localScore
          } else {
              storeNewHighscore(iCloudScore)
              result = iCloudScore
          }
          return result
      }
  </code></pre>
  
  <p>storing a new highscore</p>
  
  <pre><code>func storeNewHighscore(newScore: Int64) {
          NSUbiquitousKeyValueStore.defaultStore().setLongLong(newScore, forKey: KeyValueKeyClassification.KeyHighscore.toRaw())
          NSUserDefaults.standardUserDefaults().setInteger(Int(newScore), forKey: KeyValueKeyClassification.KeyHighscore.toRaw())
          if NSUbiquitousKeyValueStore.defaultStore().synchronize() {
              println("Synched Successfully")
          }
      }
  </code></pre>
  
  <p>for some reason however the scores are not synched. </p>
  
  <ul>
  <li>no errors</li>
  <li>no crashes</li>
  <li>no null values</li>
  </ul>
  
  <p>i always get the highest score from the current device, never the one achieved on others.</p>
  
  <p>could the reason be within itunesconnect or is something wrong with my code? i am using an ipad and an iphone for testing, both logged in to my own icloud account.</p>
  
  <p>i am registering for the changes like this:</p>
  
  <pre><code>func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -&gt; Bool {
          // Override point for customization after application launch.
  
          NSNotificationCenter.defaultCenter().addObserver(self, selector: "icloudKeyValueChanged", name: NSUbiquitousKeyValueStoreDidChangeExternallyNotification, object: nil)
          if NSUbiquitousKeyValueStore.defaultStore().synchronize() {
              println("initial Synched Successfully")
          }
  
          return true
      }
  </code></pre>
  
  <p>but the function 'icloudKeyValueChanged' is never called.</p>
  
  <p>iCloud Capabilities all are ok as it seems:</p>
  
  <p><img src="https://i.stack.imgur.com/6yp6P.png" alt="enter image description here"></p>