undead index

Hi,

pg_upgrade brakes with the following error:

pg_upgrade 8.4.5 to 9.0.4:
Restoring user relation files
/data1/postgres/pgsql/foo/data_8.4/base/11564/2613 ^M
/data1/postgres/pgsql/foo/data_8.4/base/11564/2683
Could not find foo.bar_idx in old cluster

This index was deleted several weeks ago.

server_version | 8.4.5

foo=# select * from pg_class where relname = 'bar_idx';
(No rows)

after pg_dumpall|psql from 8.4 to 9.0 the undead index revived on the target
DB:

server_version | 9.0.4

foo=# select * from pg_class where relname = 'bar_idx';
-[ RECORD 1 ]---+------------------------------------
relname | bar_idx
relnamespace | 16409

Besides the question how this could happen, Is there another way to correct
this without using dump|restore?
I'd like to get pg_upgrade working.

Regards, Jens