asterisk users - Jul 2004 - Language

I have problem setting the language for the SIP channel - Sip.conf

I have set there language=xxx

and I've recorded some mesages for voice mail in xxx language.
But when they are played they are in en.

But this works for  language=xxx in zapata.conf (When these  messages 
are played to the FXS)
Any suggestions ?

I've tried to put SetLanguage in extension.conf But it causes me some 
troubles with the dialplan.