Strange behaviour of addref called from shell script

Why might refdbd be showing this error (multiplied by 837):

BEGIN
LOCK TABLES t_refdb WRITE, t_author WRITE, t_keyword WRITE, t_periodical 
WRITE, t_user WRITE, t_xauthor WRITE, t_xkeyword WRITE, t_xuser WRITE, 
t_note WRITE, t_xnote WRITE, t_link WRITE, t_xlink WRITE, 
refdb.t_journal_words WRITE
SELECT refdb_id, refdb_citekey FROM t_refdb WHERE 
refdb_citekey='DIJK2000MODELS-OF-DEMOC'
INSERT INTO t_refdb (refdb_type,refdb_citekey) VALUES 
('DUMMY','DUMMYJeremy-Malcolms-Computer.local11086')
1062: Duplicate entry 'DUMMYJeremy-Malcolms-Computer.local11086' for key 2
inserting reference data failed
ROLLBACK
UNLOCK TABLES
failed processing dataset

when I try to add my references using a shell script, but NOT when I run 
the exact same command from the bash prompt?  My command is refdbc -c 
/bin/cat -d thesis -C addref Thesis.ris, and this problem has only 
arisen since the most recent upgrade to 0.9.9-pre2.

-- 
Jeremy Malcolm LLB (Hons) B Com
Internet and Open Source lawyer, IT consultant, actor
host -t NAPTR 1.0.8.0.3.1.2.9.8.1.6.e164.org|awk -F! '{print $3}'

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