pg_autovacuum w/ dbt2

After all this time I finally got around to vacuuming the database
with dbt2 with pg_autovacuum. :)
http://www.osdl.org/projects/dbt2dev/results/dev4-010/215/

Doesn't look so good though, probably because I'm not using optimal
settings with pg_autovacuum. So far I have only tried the default
settings (running without any arguments, except -D).

The only thing that's peculiar is a number of unexpected rollbacks
across all of the transactions. I suspect it was something to do with
these messages coming from pg_autovacuum:

[2004-12-20 15:48:18 PST] ERROR: Can not refresh statistics information from the database dbt2.
[2004-12-20 15:48:18 PST] The error is [ERROR: failed to re-find parent key in "pk_district"
]

This is with 8.0rc1. I can get rc2 installed since it just came out.
So let me know what I can try and what not.

Mark