Users in pg_shadow

I have a cron script set up to run VACUUM ANALYZE on two databases that appear
to work fine except for a couple of messages that show up in the log:

FATAL 1:  SetUserId: user 'newsltr' is not in 'pg_shadow'
FATAL 1:  SetUserId: user 'wcgc_pg' is not in 'pg_shadow'

newsltr and wcgc_pg are the respective names of the databases, there are no
users with these names.  This is on a postgresql-7.0.2 running on a Red Hat 6.2

I've seen no problems resulting from this but I would like to understand why.

--
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Scott Holmes                       http://www.pacificnet.net/~sholmes
                                   sholmes@pacificnet.net

  Independent Programmer/Analyst                  Passport 4GL
  PHP HTML Composer                PostgreSQL     Informix 4GL, SQL
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