Unable to delete row on 7.3.2 with schemas

Postgres 7.3.2:

table2 has a foreign key on table1 (id).

Trying to delete a value from table1, not actually referenced from table2.

psql -U usr db

db=> DELETE FROM table1 WHERE id=7;
LOG: query: DELETE FROM table1 WHERE id=7;
LOG: query: SELECT 1 FROM ONLY "public"."table1" x WHERE "id" = $1 FOR UPDATE
OF x
LOG: query: SELECT 1 FROM ONLY "public"."table2" x WHERE "id" = $1 FOR UPDATE
OF x
ERROR: usr: permission denied

db=> \dp table2

Access privileges for database "db"
Schema | Table | Access privileges
--------+------------+-------------------------------------------------------------------
public | table2 | {=,...,usr=arwd,...}
(1 row)

db=> \db table1
Access privileges for database "db"
Schema | Table | Access privileges
--------+------------+-------------------------------------------------------------------
public | table1 | {=,...,usr=arwd,...}
(1 row)

Same happens if I do this as db super-user. "usr" is also an schema name.

Can't see why. Any ideas? Some obvious overlook?

Thanks in advance!

Fernando Schapachnik
Proyecto de Informática
Ministerio de Economía