because the postgresql-data is not installed, linuxconf complains when you try to apply the changes (i.e., add a new user). I get the following message when I view the log: Starting postgresql service: /usr/bin/postmaster does not find the database system. Expected to find it in the PGDATA directory "/var/lib/pgsql", but unable to open file with pathname "/var/lib/pgsql/base/template1/pg_class". No data directory -- can't proceed. postmaster []
Those messages are only being reported via linuxconf, they do not originate with linuxconf.
I believe this problem is fixed by starting postgresql differently in postgresql-6.5.2 and later.