BUG #4523: TO_CHAR function : the ".US" format returns incorrect value

The following bug has been logged online:

Bug reference:      4523
Logged by:          Moussard
Email address:      evelyne.moussard@cartes-bancaires.com
PostgreSQL version: 8.3.3
Operating system:   i686-redhat-linux-gnu
Description:        TO_CHAR function : the ".US" format returns incorrect
value
Details:

Using the "TO_CHAR" function, the ".US" format doesn't display the correct
value for the microseconds part of a timestamp value.

For exemple :

CREATE TABLE  TITEST
  (
     DH_DEBUT        TIMESTAMP(0),
     TS_DEBUT         TIMESTAMP(6),
     D_DEBUT         DATE
  )
WITH (FILLFACTOR = 90);

truncate table titest;
insert into titest (ts_debut) values ('31/12/2008 23:59:58.123457');

select ts_debut from titest;

Returns the correct value : 2008-12-31 23:59:58.123457

select to_char(ts_debut,'dd/mm/yyyy HH24:MI:SS.US') from titest;

Returns a wrong value : 31/12/2008 23:59:58.123456
(the last number is not correct : 6 instead of 7).