ident auth not working on 7.3.1

I can't get ident auth to work on 7.3.1. I'm using Linux 2.4 (RedHat 7.3).

     [postgres@calvin data]$ unset PGDATABASE PGHOST PGPORT PGUSER
     [postgres@calvin data]$ killall -HUP postmaster
     [postgres@calvin data]$ egrep '^[^#]' pg_hba.conf
     local all all trust
     [postgres@calvin data]$ psql template1
     Welcome to psql 7.3.1, the PostgreSQL interactive terminal.

     Type:  \copyright for distribution terms
            \h for help with SQL commands
            \? for help on internal slash commands
            \g or terminate with semicolon to execute query
            \q to quit

     template1=# \q
     [postgres@calvin data]$ vim pg_hba.conf
     [postgres@calvin data]$ killall -HUP postmaster
     [postgres@calvin data]$ egrep '^[^#]' pg_hba.conf
     local all all ident
     [postgres@calvin slamb]$ id
     uid=26(postgres) gid=26(postgres) groups=26(postgres)
     [postgres@calvin slamb]$ psql template1
     psql: FATAL:  IDENT authentication failed for user "postgres"

What could cause this?

Thanks,
Scott