Problems while restoring databases

Hi everyone !

I am facing a problem after a lot of research has not found a solution.
I hope some of you can enlighten me
I will hold my position in 3 part: what I want, what I run, which is a
problem.

First of all I want to:

Back up a database with all information (structure, data, functions,
triggers) in a "dump"
Restore the same data (structure, data, trigger, etc ...) into a new
database with a different name (ex: src=foo ; dst= bar)

So far not rocket science.

Then what I do:
pg_dump -i -F c -i -h ***.***.***.*** -p #### -U #### -f c:\dump.bak
mySourceBase

A creation of new base like this :

CREATE DATABASE "testingBackup"

WITH OWNER = postgres

ENCODING = 'UTF8'

TABLESPACE = pg_default

LC_COLLATE = 'French_France.1252'

LC_CTYPE = 'French_France.1252'

CONNECTION LIMIT = -1;

And finally :

pg_restore -F c -h ##### -p #### -U #### -d testingBackup C:\dump.bak

What problems i got

pg_restore: [archiver (db)] Error while PROCESSING TOC:

pg_restore: [archiver (db)] Error from TOC entry 626; 2612 16386 PROCEDURAL
LANG

UAGE plpgsql postgres

pg_restore: [archiver (db)] could not execute query: ERREUR: language
"plpgsql" already exists

Command was:

CREATE PROCEDURAL LANGUAGE plpgsql;

WARNING: errors ignored on restore: 1

In fact there is no problem since all data is restored but in a goal of
"cleanliness" I want to clean this mess and finally get no error.
To this end I am open to your suggestions.

Thank you in advance for your help, and I apologies for my bad English.

Jean-Yves