problem with array query

Hi Folks

According to the 8.3 docs I should be able to write:
select * from tblretrain where 'ms-ap-t2-02c9' NOT IN (owners);

where owners is an array per the following definition

CREATE TABLE tblretrain
(
pkretrainid integer NOT NULL,
mailid integer NOT NULL,
train_to smallint NOT NULL,
owners character varying(1024)[],
bayes_trained boolean DEFAULT false,
contents text NOT NULL,
CONSTRAINT tblretrain_pk PRIMARY KEY (pkretrainid)
)

The problem is that it generates an error:

ERROR: array value must start with "{" or dimension information
********** Error **********
ERROR: array value must start with "{" or dimension information
SQL state: 22P02

It seems as though postgres is not recognising owners as an array.

Any suggestions please ?
regards
Grant