Strange Type Mismatch on Insert

Can anyone see what is the problem with the following insert?

gmp=# insert into data (site, gmp_id, item, category, gmp) values
('Rochester', 22, 'Design fee', 12, 40000.00);
ERROR:  Unable to identify an operator '=' for types 'text' and 'int4'
        You will have to retype this query using an explicit cast
gmp=# \d data
                    Table "data"
 Attribute |     Type      |        Modifier
-----------+---------------+------------------------
 site      | text          | not null
 gmp_id    | integer       | not null default 9999
 co_id     | text          | not null default 'N/A'
 item      | text          | not null
 category  | integer       |
 gmp       | numeric(12,2) | default 0
 co_status | char(1)       |
Index: data_pkey

jeffe@kiyoko=> psql -V
psql (PostgreSQL) 7.0.0
jeffe@kiyoko=> uname -a
FreeBSD kiyoko.la.verio.net 4.0-STABLE FreeBSD 4.0-STABLE #0: Thu Apr 27
10:44:07 CDT 2000