Chef Server 11.04 postgresql log errors

Any clues as to what is causing these in
/var/log/chef-server/postgresql? We have a pretty simple setup with 2
so far. The whole setup was pristine starting at 11.04, not
upgraded with baggage from 10.x, etc.

Repeating regularly (something’s trying to connect to PostgreSQL
as ‘chef’ which doesn’t exist?):

2013-08-28_12:12:03.01423 FATAL: role “chef” does not exist

More sporadic (it’s clear what this is, the question is why):

2013-08-23_16:17:36.91487 STATEMENT: INSERT INTO checksums(org_id,
2013-08-23_16:17:36.91487 VALUES ($1, $2)
2013-08-23_16:17:36.91612 ERROR: duplicate key value violates unique
constraint "checksums_pkey"
2013-08-23_16:17:36.91613 DETAIL: Key (org_id,
checksum)=(00000000000000000000000000000000, e63ec30559419d397
22fa113306d4a22) already exists.