BUG #4119: Add foreign key fails for non-presence of a record that does exist.

The following bug has been logged online:

Bug reference: 4119
Logged by: Buk
Email address: p9e883002(at)sneakemail(dot)com
PostgreSQL version: 8.2.4,
Operating system: XP SP1
Description: Add foreign key fails for non-presence of a record that
does exist.
Details:

I'm trying to run this:

big_db=# ALTER TABLE word_doc ADD FOREIGN KEY (word_id) REFERENCES words
(word_id) ON UPDATE RESTRICT ON DELETE RESTRICT;

I'm getting this error:

ERROR: insert or update on table "word_doc" violates foreign key constraint
"word_doc_word_id_fkey"
DETAIL: Key (word_id)=(65935) is not present in table "words".

And yet, there is the "missing" key:

big_db=# select * from words where word_id = 65935;
word_id | word
---------+----------------
65935 | bioremediation
(1 row)

What am I doing wrong??

Cheers, Buk.