FOREIGN KEY errors.

When trying to alter a table and add a foreign key, I am getting this
error if the table has any data in it:

playpen=# alter table message add FOREIGN KEY (pod,originator)
REFERENCES usertable (podkey,userkey);
NOTICE: ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s)
for FOREIGN KEY check(s)
ERROR: constraint <unnamed>: table usertable does not have an attribute
originator

If I do the alter before I put any data in the table:

playpen=# alter table message add FOREIGN KEY (pod,originator)
REFERENCES usertable (podkey,userkey);
NOTICE: ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s)
for FOREIGN KEY check(s)
CREATE

playpen=# select version();
version
---------------------------------------------------------------------
PostgreSQL 7.0.3 on i686-pc-linux-gnu, compiled by gcc egcs-2.91.66
(1 row)

Reversing the order creates a different message:
playpen=# alter table message add FOREIGN KEY (originator,pod)
REFERENCES usertable (userkey,podkey);
NOTICE: ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s)
for FOREIGN KEY check(s)
ERROR: constraint <unnamed>: table usertable does not have an attribute
pod

Am I just misunderstanding how to use FOREIGN KEY? Then why would it
work one time and not the other?

http://www.postgresql.org/docs/aw_pgsql_book/node159.html doesn't have
any column names after 'refrences <tablename>'.

--
Joseph Shraibman
jks(at)selectacast(dot)net
Increase signal to noise ratio. http://www.targabot.com