I've tried moving freeUDFlib.dll into various folders just to make sure it was in a visible path.

I'm having trouble using a UDF in this Stored Procedure. I can see F_AddMonth in the UDF list, and the procedure compiles, but when I try to commit, I get this message:
Invalid token.
invalid request BLR at offset 188.
function F_ADDMONTH is not defined.
module name or entrypoint could not be found.

I don't know if I should include some kind of declaration, or if I have a problem with the DLL. I'm using Firebird 2.1. I had this problem once with FB 2.0 and solved it by changing the character set to "none". That hasn't helped since switching to 2.1.

My CODE:

create procedure P_UTIL_RENEW_AUTO_RENEWAL
as
declare variable ipolperiod integer;
declare variable bRenew varchar(1);
declare variable dtrenewdate date;
declare variable dttoday date;
BEGIN
select AUTO_UPDATE_RENEWALS from POLICYDAT into :bRenew;
select renewal from deta into :dtrenewdate;
select current_date from RDB$DATABASE into dtToday;

UPDATE deta
SET deta.renewal = (F_AddMonth(:dtrenewdate, :ipolperiod ))
where deta.renewal < :dtToday;
END