trying to upgrade and keep large object IDs intact...

We're trying to move from 7.1.3 to 7.2, and we have a table that stores the
loid from pg_largeobject. The table that references the loid is storing it
as a text field.  When we go through the dump/restore process, the loid (for
the attachment, in pg_largeobject) is changed in the new database, which
causes inconsistencies in our data.

We're doing the pg_dump like this:
pg_dump --blobs --format=c --quotes --oids --compress=5 quickview > qv.dump

and the restore like this:
pg_restore -o --dbname=quickview --superuser=pgsql72 < qv.dump

The field (in table "attachments") that references the loid (in
pg_largeobject) is storing the loid as text-- is that possibly what's making
it difficult for us to do this upgrade?

I've read the man pages for pg_dump/pg_restore, as well as searched the web
and the postgres web site, but I'm still lacking the necessary clue to make
this upgrade succeed.  Pointers to additional documents happily accepted.

-ron

        Table "attachments"
 Attribute  |     Type     | Modifier
------------+--------------+----------
 id         | integer      |
 atype      | character(1) |
 data       | text         |
 compressed | boolean      |
Index: attachments_id
Rule: att_lo_remover
Trigger: RI_ConstraintTrigger_11991716