bug in 7.4 ...

I have seen that a bug related to duplicated keys is in 7.4rc2. As far 
as I have seen a bug like that has already been discovered during the 
7.3 era. Is this bug going to be fixed?

Here s the description:

DROP TABLE public.testtabelle;

begin;

CREATE TABLE public.testtabelle ( c000 varchar(20), c001 int4 NOT NULL ) WITH OIDS;

create unique index prim_index_testtabelle on public.testtabelle  (c001);

delete from public.testtabelle;

insert into public.testtabelle values ('a', 1);
insert into public.testtabelle values ('b', 2);
insert into public.testtabelle values ('c', 3);

-- insert into public.testtabelle values ('d', 4);
insert into public.testtabelle values ('e', 5);
insert into public.testtabelle values ('d', 4);

delete from public.testtabelle where c001 = 3;

update public.testtabelle set c001 = c001 - 1 where c001 > 3;

select * from public.testtabelle;

commit;

this will fail on Pg 7.3.3 and Pg 7.4 rc2. However, if 4 is inserted 
before 5 it will work for some reason.

does anybody have an explanation for this behaviour?
Cheers,
    Hans

-- 
Cybertec Geschwinde u Schoenig
Ludo-Hartmannplatz 1/14, A-1160 Vienna, Austria
Tel: +43/2952/30706 or +43/660/816 40 77
www.cybertec.at, www.postgresql.at, kernel.cybertec.at