OAuthException: (#200) The user hasn't authorized the application to perform this action

Hi i am continually experiencing this problem with ultimate facebook.

My client has mulitple sites that he wants to automatically post to specific facebook page walls

site a to facebook wall a
site be to facebook wall b

I got facebook a working first time, since then with b,c and d i am having issues and get the OAuthException: (#200) The user hasn't authorized the application to perform this action in the log, despite all being authorized.

any thoughts?