Please Help - Error saying Failed to create request token

My yahoo contacts api used to work properly.Since last week it stopped working and shows the following error
"[02-Jun-2011 00:41:20] ERROR - Failed to create request token: unknown problem".

I deleted the existing project and created a new one with scope to read the contacts and carefully pasted the consumer key and secret.Still its not working.

Could somebody help me with this..
Thanks in advance.