Mixed Pg-9.1.2 and 8.4.4 environment

We are in the process of migrating our various servers to
a kvm host with guest vms. The new guests run pg-9.1.2
under CentOS-6.2. However, our off site warm spares are
still running pg-8.4.4 under CentOS-5.7.

We have an automated transfer routine that dumps the live
database, now running v.9.1.2, and sends the dump file to
the off site host. There the dump is restored to an 8.4.4
version.

My question: Is their a way to specify a pg_dump option
to retain compatibility with a lower version pg database?
Alternatively, can one install a higher level pg_dump in
an otherwise 8.4.4 installation?

The reason for the question is that we are receiving these
warnings:

pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 257; 3079
12506 EXTENSION plpgsql
pg_restore: [archiver (db)] could not execute query:
ERROR: syntax error at or near "EXTENSION"
LINE 1: DROP EXTENSION plpgsql;
^
Command was: DROP EXTENSION plpgsql;
pg_restore: [archiver (db)] could not execute query:
ERROR: syntax error at or near "EXTENSION"
LINE 1: CREATE EXTENSION IF NOT EXISTS plpgsql WITH SCHEMA
pg_catalo...
^
Command was: CREATE EXTENSION IF NOT EXISTS plpgsql
WITH SCHEMA pg_catalog;
pg_restore: [archiver (db)] Error from TOC entry 3473; 0 0
COMMENT EXTENSION plpgsql
pg_restore: [archiver (db)] could not execute query:
ERROR: syntax error at or near "EXTENSION"
LINE 1: COMMENT ON EXTENSION plpgsql IS 'PL/pgSQL
procedural languag...
^
Command was: COMMENT ON EXTENSION plpgsql IS 'PL/pgSQL
procedural language';
pg_restore: [archiver (db)] Error from TOC entry 3462; 0
20928 TABLE DATA wiki_content_versions
hll_redmine_db_admin
pg_restore: [archiver (db)] COPY failed: ERROR: invalid
input syntax for type bytea
CONTEXT: COPY wiki_content_versions, line 1, column data:
"\x68312e205b5b57696b6953746172747c48617274652026204c796e65204c696d697465642053746172745d5d0d0a0d0a0d..."
WARNING: errors ignored on restore: 4

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James B. Byrne mailto:ByrneJB(at)Harte-Lyne(dot)ca
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