Postgresql on solaris 8

We have installed Postgres 7.1 on a SUN Solaris 6 server.  This works well.
We have also transferred the same binary/libraries to a server running
Solaris 8.  This also works well.  However we have noticed that 2 postmaster
processes are created when the postmaster is run.  The second of which is a
child of the first.  This does not occur when running on Solaris 6, only 1
postmaster runs.  Could you tell us why it does this?

Thanks Adam Stephenson

Thales Defence (Wells) DISCLAIMER: The information in this message is
confidential and may be legally privileged. It is intended solely for the
addressee.  Access to this message by anyone else is unauthorised.  If you
are not the intended recipient, any disclosure, copying, or distribution of
the message, or any action or omission taken by you in reliance on it, is
prohibited and may be unlawful.  Please immediately contact the sender if
you have received this message in error. Thank you.