7.4 Beta1: variable not found in subplan target lists

Hey again,

Received this error:

Aug 6 16:24:55 thunder postgres[7835]: [11-1] ERROR: variable not
found in subplan target lists

during this query:

$dbh->do( qq/
DELETE FROM temp_obs_v
WHERE file_id IN
(SELECT file_id
FROM temp_obs_v NATURAL JOIN files
WHERE group_id = $group_id
AND pair_id = $pair_id) /);

on the 15th iteration (the previous 14 worked fine).

It is repeatable. Something stupid again (other than the duplicate
indexes)?

tassiv=# explain DELETE FROM temp_obs_i
tassiv-# WHERE file_id IN
tassiv-# (SELECT file_id
tassiv(# FROM temp_obs_i NATURAL JOIN files
tassiv(# WHERE group_id = 3
tassiv(# AND pair_id = 25)
tassiv-# ;
ERROR: variable not found in subplan target lists

tassiv=# \d temp_obs_i
Table "public.temp_obs_i"
Column | Type | Modifiers
---------+---------+------------------------------------------------
x | real | not null
y | real | not null
imag | real | not null
smag | real | not null
loc | spoint | not null
obs_id | integer | not null default nextval('"obs_id_seq"'::text)
file_id | integer | not null
use | boolean | default false
solve | boolean | default false
star_id | integer |
mag | real |
Indexes:
"temp_obs_i_file_id_index" btree (file_id)
"temp_obs_i_index" gist (loc)
"temp_obs_i_loc_index" gist (loc)
"temp_obs_i_obs_id_index" btree (obs_id)
Foreign-key constraints:
"temp_obs_i_files_constraint" FOREIGN KEY (file_id) REFERENCES
files(file_id) ON DELETE CASCADE Inherits: obs_root

tassiv=# \d files
Table "public.files"
Column | Type | Modifiers

----------+--------------------------+---------------------------------
---------------------- file_id | integer | not null
default nextval('"files_file_id_seq"'::text) group_id | integer
| pair_id | integer |
date | timestamp with time zone | not null
name | character varying | not null
ra_min | real | default 0
ra_max | real | default 0
dec_min | real | default 0
dec_max | real | default 0
Indexes:
"files_pkey" primary key, btree (file_id)
"files_name_key" unique, btree (name)
"files_id_index" btree (file_id, group_id, pair_id)
"files_range_index" btree (ra_min, ra_max, dec_min, dec_max)
Foreign-key constraints:
"$1" FOREIGN KEY (group_id) REFERENCES groups(group_id) ON DELETE
CASCADE "$2" FOREIGN KEY (pair_id) REFERENCES pairs(pair_id) ON
DELETE CASCADE

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