Error Message Using pg_dumpall

I'm not on these lists, please reply to me directly if you have any information:

We are attempting to upgrade from version 7.1 to 7.2 of Postgres.  Part of the upgrade is to perform a pg_dumpall and dump the data, and then reload it back into 7.2.  When I issue the command, I get the following error.  Searches have yielded me nothing, and I'm wondering if anyone has a clue as to what is causing this.

Thanks in advance.

------(snip)------------------------

new_largo:/var/lib/pgsql >pg_dumpall > /home/largo/dkr.dump
ERROR:  Relation 'pg_user' does not exist
getDatabase(): SELECT failed.  Explanation from backend: 'ERROR:  Relation 'pg_u
ser' does not exist
'.
----(snip)------------------------------

Dave Richards
Systems Administrator
City of Largo, Florida
drichard@largo.com