title: iOS SA_OAuthTwitterEngine authenticating, but not posting, and no delegate callbacks
body: <p>I had <code>SA_OAuthTwitterEngine</code> seemingly working fine in my iOS app, but a couple of months ago, it stopped working (EDIT: not working in iOS 4 or iOS 5, and no code changed in the app prior to the malfunction). It is authenticating and storing creds fine, and passing them to my database service just fine. When I attempt to post a Tweet, everything logs fine as if it's going through the proper process. All tokens and usernames, etc. getting passed correctly. However, I am seeing no posts on Twitter. I am using a date stamp in the post and have tried this on two different user accounts without seeing a single post from either account. Interestingly, the <strong><code>MGTwitterEngineDelegate</code></strong> callbacks (<code>requestSucceeded:</code> and <code>requestFailed:</code>) are not being called. I put breakpoints in MGTwitterEngine's <code>connection:didReceiveResponse:</code>, <code>connection:didReceiveData:</code>, and <code>connection:didFailWithError:</code> to see if it was just a delegate assignment issue, but those breakpoints were never reached, so the app is seemingly getting no response from Twitter, despite the fact that I can log a Connection Identifier returned from the engine's sendUpdate: method every single time. If I can get the delegate to receive the connection's response, maybe I'll see an error. SO that's what I have been banging my head on all day. Any help would be appreciated. </p>
  
  <p>Code here:</p>
  
  <pre><code>- (void)postTweetToTwitter 
  {
      if (![[NSUserDefaults standardUserDefaults] objectForKey:TWITTER_USER]) {
          [[NSNotificationCenter defaultCenter] postNotificationName:@"ShowSettings" object:nil];
          return; //Makes sure user data is stored in NSUserDefaults before continuing, if not, settings will prompt for authentication
      }
  
      NSString *formattedDateString = [NSDateFormatter localizedStringFromDate:[NSDate date] dateStyle:kCFDateFormatterShortStyle timeStyle:kCFDateFormatterNoStyle];
      NSString *tweetMessage = [NSString stringWithFormat:@"%@: Tweet message goes here.",  formattedDateString];  
  
      if(!_engine){
          _engine = [[SA_OAuthTwitterEngine alloc] initOAuthWithDelegate:self];
          _engine.consumerKey    = kOAuthConsumerKey;
          _engine.consumerSecret = kOAuthConsumerSecret;      
      }
  
      UIViewController *controller = [SA_OAuthTwitterController controllerToEnterCredentialsWithTwitterEngine: _engine delegate: self];    
      if (controller)
          [self presentModalViewController: controller animated: YES];
      else {
          NSString *twitterConnectionIdentifier = [_engine sendUpdate:[NSString stringWithString:tweetMessage]];  
          NSLog(@"Twitter Connection Identifier : %@", twitterConnectionIdentifier);
      }
  }
  
  - (NSString *) cachedTwitterOAuthDataForUsername: (NSString *) username {      
      NSString *authData = [[NSUserDefaults standardUserDefaults] objectForKey:TWITTER_USER];
      if (authData) {
          return authData;
      } else return [NSString stringWithString:@"No Twitter Data"];
      //This just won't do anything, but we avoid this case in the first if statement above.   
  }
  </code></pre>