Maybe the auth request is missing params :
It seems that twitter doesn’t accept the headers to get a token.
here’s the raw data form the response headers,
2013-02-21 17:30:30.378 Corona Simulator[69116:707] set-cookie: k=10.34.253.124.1361464230253360; path=/; expires=Thu, 28-Feb-13 16:30:30 GMT; domain=.twitter.com, guest\_id=v1%3A136146423026234752; domain=.twitter.com; path=/; expires=Sun, 22-Feb-2015 04:30:30 GMT, \_twitter\_sess=BAh7CDoPY3JlYXRlZF9hdGwrCHiBl%252F08ASIKZmxhc2hJQzonQWN0aW9uQ29u%250AdHJvbGxlcjo6Rmxhc2g6OkZsYXNoSGFzaHsABjoKQHVzZWR7ADoHaWQiJTZk%250AZGU1ZGNkNWU1MjFhMTQ0NWFhYWFkNjQ0YjdhYTE3--4d46e01c66271603dd7954182ce2d7ce357cb716; domain=.twitter.com; path=/; HttpOnly
2013-02-21 17:30:30.378 Corona Simulator[69116:707] server: tfe
2013-02-21 17:30:30.378 Corona Simulator[69116:707] x-mid: b0e635df85aca17de527b5570808f31596e76e61
2013-02-21 17:30:30.378 Corona Simulator[69116:707] date: Thu, 21 Feb 2013 16:30:30 GMT
2013-02-21 17:30:30.379 Corona Simulator[69116:707] last-modified: Thu, 21 Feb 2013 16:30:30 GMT
2013-02-21 17:30:30.379 Corona Simulator[69116:707] x-transaction: c1fd8a4ffcee681b
2013-02-21 17:30:30.379 Corona Simulator[69116:707] content-length: 44
2013-02-21 17:30:30.379 Corona Simulator[69116:707] expires: Tue, 31 Mar 1981 05:00:00 GMT
2013-02-21 17:30:30.379 Corona Simulator[69116:707] cache-control: no-cache, no-store, must-revalidate, pre-check=0, post-check=0
2013-02-21 17:30:30.380 Corona Simulator[69116:707] content-type: text/html; charset=utf-8
2013-02-21 17:30:30.380 Corona Simulator[69116:707] vary: Accept-Encoding
2013-02-21 17:30:30.380 Corona Simulator[69116:707] status: 401 Unauthorized
2013-02-21 17:30:30.380 Corona Simulator[69116:707] pragma: no-cache
2013-02-21 17:30:30.380 Corona Simulator[69116:707] x-runtime: 0.01569
2013-02-21 17:30:30.380 Corona Simulator[69116:707] x-frame-options: SAMEORIGIN
[import]uid: 3638 topic_id: 36166 reply_id: 143722[/import]