bug (?) with RULEs with WHERE

I cannot use RULEs with WHERE clauses. What's wrong? Is this a bug? I also
had this problem with 7.1.1. The documentation says this should work.

foo=# SELECT version();
version
---------------------------------------------------------------------
PostgreSQL 7.1.3 on i686-pc-linux-gnu, compiled by GCC egcs-2.91.66
(1 row)

foo=# CREATE TABLE a(foo integer);
CREATE
foo=# CREATE TABLE b(foo integer);
CREATE
foo=# CREATE VIEW c AS SELECT foo FROM a;
CREATE
foo=# CREATE RULE d AS ON INSERT TO c WHERE new.foo=5 DO INSTEAD SELECT foo FROM b;
CREATE
foo=# INSERT INTO c VALUES (5);
ERROR: Cannot insert into a view without an appropriate rule
foo=# INSERT INTO c VALUES (6);
ERROR: Cannot insert into a view without an appropriate rule

TIA, Zoltan

--
Kov\'acs, Zolt\'an
kovacsz(at)pc10(dot)radnoti-szeged(dot)sulinet(dot)hu
http://www.math.u-szeged.hu/~kovzol
ftp://pc10.radnoti-szeged.sulinet.hu/home/kovacsz