Startup Failure - Mailing list pgsql-admin

Greetings all -

when I attempt to start my Postgresql-7.0.2 server I receive the following
error:

FATAL: StreamServerPort: bind() failed: Operation not permitted
         Is another postmaster already running on that port?
         If not, remove socket node (/tmp/.s.PGSQL.5432) and retry.
/usr/local/pgsql/bin/postmaster: cannot create UNIX stream port

I am running Mandrake Linux 7.0 with kernel 2.3.50 on a dual Pentium 200
MMX system, 256Mb RAM.

Thanks in advance for any help!

Joel