title: kReachabilityChangedNotification is called multiple times
body: <p>I'm using the <code>Reachability</code> classes for checking when I got an internet connection en when it goes down.</p>
  
  <p>This is my code:</p>
  
  <pre><code>      IN VIEW DID LOAD:
  
          internetReachable = [Reachability reachabilityForInternetConnection];
          [internetReachable startNotifier];
  
          // check if a pathway to a random host exists
          hostReachable = [Reachability reachabilityWithHostname:@"www.google.com"];
          [hostReachable startNotifier];
  
  
      Then the notification method
      -(void) checkNetworkStatus:(NSNotification *)notice
      {
          // called after network status changes
          NetworkStatus internetStatus = [internetReachable currentReachabilityStatus];
          switch (internetStatus)
          {
              case NotReachable:
              {
                  NSLog(@"The internet is down. IN AGENDA");
                  self.internetActive = NO;
  
                  break;
              }
              case ReachableViaWiFi:
              {
                  NSLog(@"The internet is working via WIFI.IN AGENDA");
                  self.internetActive = YES;
  
                  break;
              }
              case ReachableViaWWAN:
              {
                  NSLog(@"The internet is working via WWAN.IN AGENDA");
                  self.internetActive = YES;
  
                  break;
              }
          }
  
          NetworkStatus hostStatus = [hostReachable currentReachabilityStatus];
          switch (hostStatus)
          {
              case NotReachable:
              {
                  NSLog(@"A gateway to the host server is down.IN AGENDA");
                  self.hostActive = NO;
  
                  break;
              }
              case ReachableViaWiFi:
              {
                  NSLog(@"A gateway to the host server is working via WIFI.IN AGENDA");
                  self.hostActive = YES;
  
                  break;
              }
              case ReachableViaWWAN:
              {
                  NSLog(@"A gateway to the host server is working via WWAN.IN AGENDA");
                  self.hostActive = YES;
  
                  break;
              }
          }
      }
  
  And finally how I add en remove the observer
  -(void)viewWillAppear:(BOOL)animated{
      [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(checkNetworkStatus:) name:kReachabilityChangedNotification object:nil];
  }
  -(void)viewDidDisappear:(BOOL)animated{
      [[NSNotificationCenter defaultCenter] removeObserver:self name:kReachabilityChangedNotification object:nil];
  }
  </code></pre>
  
  <p><strong>THE PROBLEM</strong></p>
  
  <p>It seems like that the viewcontroller gets the notification multiple times. 
  This is my NSLOG</p>
  
  <pre><code>2014-01-04 10:32:16.299 Adsolut[10009:333b] CALLED reachabilityChanged
  2014-01-04 10:32:16.299 Adsolut[10009:470b] CALLED reachabilityChanged
  2014-01-04 10:32:16.300 Adsolut[10009:70b] The internet is down. IN AGENDA
  2014-01-04 10:32:16.301 Adsolut[10009:70b] A gateway to the host server is down.IN AGENDA
  2014-01-04 10:32:16.301 Adsolut[10009:70b] The internet is down. IN AGENDA
  2014-01-04 10:32:16.302 Adsolut[10009:70b] A gateway to the host server is down.IN AGENDA
  2014-01-04 10:32:16.313 Adsolut[10009:470b] CALLED reachabilityChanged
  2014-01-04 10:32:16.313 Adsolut[10009:4a03] CALLED reachabilityChanged
  2014-01-04 10:32:16.314 Adsolut[10009:70b] The internet is working via WIFI.IN AGENDA
  2014-01-04 10:32:16.314 Adsolut[10009:333b] CALLED reachabilityChanged
  2014-01-04 10:32:16.315 Adsolut[10009:70b] A gateway to the host server is down.IN AGENDA
  2014-01-04 10:32:16.314 Adsolut[10009:f63] CALLED reachabilityChanged
  2014-01-04 10:32:16.315 Adsolut[10009:70b] The internet is working via WIFI.IN AGENDA
  2014-01-04 10:32:16.316 Adsolut[10009:70b] A gateway to the host server is down.IN AGENDA
  2014-01-04 10:32:16.316 Adsolut[10009:70b] The internet is working via WIFI.IN AGENDA
  2014-01-04 10:32:16.317 Adsolut[10009:70b] A gateway to the host server is down.IN AGENDA
  2014-01-04 10:32:16.317 Adsolut[10009:70b] The internet is working via WIFI.IN AGENDA
  2014-01-04 10:32:16.318 Adsolut[10009:70b] A gateway to the host server is down.IN AGENDA
  </code></pre>
  
  <p>Can somebody help ?</p>