Passing BLOB parameter to stored procedure problem

Hi all, i got strange problem...
This is my procedure
CREATE PROCEDURE NEW_AGENCY (
NAME VARCHAR(300),
DESCRIPTION BLOB SUB_TYPE 1 SEGMENT SIZE 80,
ADDRESS_NAME VARCHAR(300),
STREET VARCHAR(300),
STREET_NO VARCHAR(300),
COUNTRY SMALLINT,
LOCATION SMALLINT,
EMAIL VARCHAR(100) CHARACTER SET ASCII,
PHONE VARCHAR(100) CHARACTER SET ASCII,
FAX VARCHAR(100) CHARACTER SET ASCII,
PERSON VARCHAR(300),
PREFFERED SMALLINT,
CREATOR INTEGER,
ZIP VARCHAR(100) CHARACTER SET ASCII,
LOGIN VARCHAR(50) CHARACTER SET ASCII,
USERROLE SMALLINT,
PASS VARCHAR(32) CHARACTER SET ASCII,
SALT VARCHAR(32) CHARACTER SET ASCII)
AS
DECLARE VARIABLE USERID INTEGER;
begin
insert into users (login,userrole,"PASSWORD",salt) values (:login,:userrole,***,:salt);
select gen_id(gen_users_id,0) from rdb$database into :userid;
insert into agencies (name,description,address_name,street,street_no,country,location,email,phone,fax,person,preffered,cr eator,dbuser,zip)
values (:name,:description,:address_name,:street,:street_no,:country,:location,:email,hone,:fax,erson,: preffered,:creator, :userid,:zip);
end

When executing the procedure: execute procedure new_agency(...) internal error is returned (leaving no clue, what happened). When i remove the description parameter it is ok.
The interesting thing is, that in different db, on the same server, i have another stored procedure which uses blob parameters and it works ok, so what am i missing??
Thanks a lot for help.