PostgreSQL stalling at boot

[Russell Davie]

Hi All

I'm getting a error when PostgreSQL starts.

as root:
XXX at XXXX:~$ sudo /etc/init.d/postgresql-7.4 start
 * Starting PostgreSQL 7.4 database server:main
pg_ctl: cannot be run as root
Please log in (using, e.g., "su") as the (unprivileged) user that will
own the server process.					[fail]


and as the postgres user:
postgres at nutz:~$ /etc/init.d/postgresql-7.4 start
chmod: changing permissions of `/var/run/postgresql': Operation not
permitted
 * Starting PostgreSQL 7.4 database server:main
Error: Could not change user id                        [fail]

This error message is in the start-up script /usr/share/postgresql-common/PgCommon.pm and its seems to be checking for group membership of "shadow" group.
The user "postgres" is a member of the shadow group and still the error occurs.

What can be done to correct this? 

TIA

Russell