pg_restore problem

Hello world,

(PostgreSQL 7.2.1-5, fully patched RedHat 7.3)

I have a db with some relations on OIDs and some BLOBs. I create a
backup with this command:

pg_dump -Fc -o -b mydb > mydb.dump

But a restore with:

pg_restore -dmydb -Fc mydb.dump

Gives this error:

CREATE DATABASE
pg_restore: connecting to database for restore
pg_restore: executing <Init> Max OID
pg_restore: creating FUNCTION "plpgsql_call_handler" ()
pg_restore: [archiver (db)] could not execute query: ERROR: function
plpgsql_call_handler already exists with same argument types
pg_restore: *** aborted because of error

Am I doing something wrong? TIA!

--
Jules Alberts.