CREATE RULE ignored, what did I do wrong

OK, below is the dump of the table definition. Several other tables reference this and have ON DELETE CASCADE. In this
tablethere is a rule for ON DELETE. The WHERE clause (NOT old.is_deleted) should always be the case, as the field is
FALSEfor all existing entries (checked).
 

The cascading deletes are all performed when I delete from this table. The rule is not. The record is NOT retained with
is_deletednow TRUE. I turned on log_statement, and saw only the queries corresponding to the cascading delete, not my
DOINSTEAD queries.
 

Does the cascade happen first?? If so, how do I get in ahead of it?

Thanks.
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smoothed_rank_episode_id | integer            | not null default
nextval('base_rank_episode_base_rank_episode_id_seq'::text)base_rank_episode_id    | integer            | not
nullsmoothing_id            | integer            | not null default 0smoothing_parameters     | double precision[] |
notnull default '{}'::double precision[]is_deleted               | boolean            | default false
 
Indexes:   "smoothed_rank_episode_pkey" primary key, btree (smoothed_rank_episode_id)   "smoothed_rank_episode_ak1"
unique,btree (base_rank_episode_id, smoothing_id, smoothing_parameters)
 
Foreign-key constraints:   "$1" FOREIGN KEY (smoothing_id) REFERENCES smoothing_algorithm(smoothing_id) ON UPDATE
CASCADEON DELETE CASCADE
 
Rules:   del_smoothed_rank_episode AS ON DELETE TO smoothed_rank_episode WHERE (NOT old.is_deleted) DO INSTEAD (DELETE
FROMhistorical_rank WHERE (historical_rank.smoothed_rank_episode_id = old.smoothed_rank_episode_id); DELETE FROM signal
WHERE(signal.signal_episode_id IN (SELECT signal_episode.signal_episode_id FROM signal_episode WHERE
(signal_episode.smoothed_rank_episode_id= old.smoothed_rank_episode_id))); UPDATE smoothed_rank_episode SET is_deleted
=true WHERE (smoothed_rank_episode.smoothed_rank_episode_id = old.smoothed_rank_episode_id); )