character varying as boolean !!! help

I think thi is a bug, I've a lot of db up with same structure and I don't have
any prioblem..
I'm using psql 7.4.2

the problem is that
i've a table

sportellounico=# \d cfp
                                      Tabella "public.cfp"
     Colonna      |       Tipo        |                       Modificatori
------------------+-------------------+----------------------------------------------------------
 cod_cfp          | integer           | not null default
nextval('public.cfp_cod_cfp_seq'::text)
 cod_procedimento | bigint            |
 testo            | character varying |


if I try to insert something it works.... but the update no....

sportellounico=# UPDATE cfp SET testo='test' AND cod_procedimento='82' where
cod_cfp='2';
ERROR:  invalid input syntax for type boolean: "test"

?????????????????

so i've try to update with a boolean value, just for test and offcourse .....

sportellounico=# UPDATE cfp SET testo=true AND cod_procedimento='82' where
cod_cfp='2';
ERROR:  column "testo" is of type character varying but expression is of type
boolean

I've try to drop the field and recreate... but nothing...
any suggestion?

Thankyou Francesco





--
Francesco Andreozzi
Tel. 347-3757481