Function does not exist

Hello,

I have create my own function name "addnewuser(integer,varchar.....)",
and when I call this function it gives me below error,

org.postgresql.util.PSQLException: ERROR: function addnewuser(bigint, character varying, character varying, character varying, character varying, character varying, character varying, unknown, character varying, character varying, character varying, character varying, character varying, character varying, character varying, character varying, character varying, character varying, character varying, character varying, integer) does not exist

Even though function exist why it gives me this error, we use postgres-8.3.7 latest.
We install postgres by .tar,gz file.

-- 
Thanks,
Dipesh
If you can't make a mistake, you can't make anything.