Error importing data in Postgres 7.0.3

Hi,

I've got a problem when doing an import of data after a backup.

bkp cmd: pg_dump mydatabase > db

Then I dropped the base and recreate one.

When doing a "psql -e mydatabase < db", an error occured when recreating
indexes.

The error is :
-------------------------
FATAL 1:  btree: failed to add item to the page in _bt_sort (2)
pqReadData() -- backend closed the channel unexpectedly.
        This probably means the backend terminated abnormally
        before or while processing the request.
connection to server was lost
-------------------------

It seems to be because if lower index is > than upper ...
The source code for this error is in :the file
"src/backend/access/nbtree/nbsort.c

I understood that this problem was existing in earlier version of Postgres,
like 6.5.*
Is there any solution to make my import of data working properly.

Thanks a lot for any help.

--
Lifo.