sohu weibo api failed

gistfile1.txt

POST /statuses/update.json HTTP/1.1
Accept: */*
User-Agent: OAuth gem v0.4.5
Content-Length: 15
Authorization: OAuth oauth_body_hash="R%2Fs6xQidsVLIcI%2BLU2rYuHj5ZUY%3D", oauth_consumer_key="kingsoft_6Apg5WMy", oauth_nonce="rouSmpDBunUrIy83hZPwCK7ngasZ3q65YrWLI46300", oauth_signature="kRIu61DfRia0K3MLHpf7cY3WcsA%3D", oauth_signature_method="HMAC-SHA1", oauth_timestamp="1334050556", oauth_token="327b503581d933cceb5a88797ad11d6b", oauth_version="1.0"
Connection: close
Host: api.t.sohu.com
Content-Type: application/x-www-form-urlencoded

status=foobar23

HTTP/1.1 401 Unauthorized
Server: nginx/0.8.54
Date: Tue, 10 Apr 2012 09:35:56 GMT
Content-Type: text/plain; charset=UTF-8
Connection: close
Content-Length: 93

{"code":401,"error":"This method requires authentication.","request":"/statuses/update.json"}