title: 401 Unauthorized using oauth with twitter on iPhone
body: <p>I use <a href="http://github.com/bengottlieb/Twitter-OAuth-iPhone/" rel="nofollow noreferrer">Twitter-OAuth-iPhone</a>.</p>
  
  <p>When I try to login on twitter with <code>SA_OAuthTwitterEngine</code>, I received an error 401
  I received the delegate call for:</p>
  
  <pre><code>- (void) OAuthTwitterController: (SA_OAuthTwitterController *) controller authenticatedWithUsername: (NSString *) username {
  </code></pre>
  
  <p>but when I try to send a tweet just after:</p>
  
  <pre><code>[_engine sendUpdate: [NSString stringWithFormat:@"Hello World"]];
  </code></pre>
  
  <p>I received an error 401:</p>
  
  <pre><code>failed with error: Error Domain=HTTP Code=401 "Operation could not be completed. (HTTP error 401.)"
  </code></pre>
  
  <p>I have check my twitter application setting:</p>
  
  <pre><code>Type:                    Client
  Default Access type:     Read &amp; Write
  </code></pre>