It looks like with 8.3, this example insert on the maintenance.html page:

  insert into pg_catalog.pg_autovacuum (vacrelid, enabled) select oid, 'f' from 
pg_catalog.pg_class where relnamespace = (select oid from pg_namespace where 
nspname = '_' || 'MyCluster') and relhasindex;

doesn't work because all the columns in pg_autovacuum are now marked as NOT 
NULL.

Here's one that does work:

INSERT INTO pg_catalog.pg_autovacuum (vacrelid, enabled, vac_base_thresh, vac_scale_factor, anl_base_thresh, anl_scale_factor, vac_cost_delay, vac_cost_limit, freeze_min_age, freeze_max_age) SELECT oid, 'f', -1, -1, -1, -1, -1, -1, -1, -1  FROM pg_catalog.pg_class WHERE relnamespace = (SELECT OID FROM pg_namespace WHERE nspname = '_' || 'MyCluster') AND relhasindex;

I'm not sure how to submit a patch, but if you let me know I can do that. :-)

-- 
Jeff Frost, Owner 	<jeff at frostconsultingllc.com>
Frost Consulting, LLC 	http://www.frostconsultingllc.com/
Phone: 650-780-7908	FAX: 650-649-1954