problem after REINDEX command

I'm having trouble with pg_statistic table.
I tried to reindex my database with command
REINDEX DATABASE EASYSHARE FORCE

I had the error : "Cannot create unique index. Table contains non-unique
values"

The index was pg_statistic_relid_att_index

In fact, when I execute the query :
SELECT starelid, staattnum, count(*) from pg_statistic group by starelid,
staattnum having count(*) > 1
I get some tuples ( 16584, 1, 2 ), ( 16584, 2, 2 ), ( 16584, 3, 2), ( 16584,
5, 2), ( 16584, 9, 2 ) and ( 16584, 10, 2 )

Relation 16584 is a user table...

The only solution is to empty the table pg_statistic and recreate the index
with the following command
CREATE UNIQUE INDEX pg_statistic_relid_att_index ON pg_statistic USING
BTREE( starelid, staattnum ) and then run REINDEX with FORCE flag...

I'm using 7.2.3

Patrick Fiche
email : patrick(dot)fiche(at)aqsacom(dot)com
tél : 01 69 29 36 18