I'm doing a java code that uses Yahoo IM SDK, however I'm getting this error:

java.io.IOException: Server returned HTTP response code: 401 for URL:
https://api.login.yahoo.com/oauth/v2/get_token?
&oauth_consumer_key=*****--
&oauth_signature_method=PLAINTEXT
&oauth_nonce=123456&oauth_timestamp=1335521870
&oauth_signature=*****%26
&oauth_version=1.0
&oauth_token=*****--

What could be the reason? Is there a new method of accessing this resource? Or is the SDK API server still up? I've been trying out for days, I have tried it with Java, Javascript code but to no avail I can't make it work.