Problem starting postmaster at startup

My postgresql database has been starting up automatically at boot time for 4
weeks until this week.  No messages in the logfile why it doesn't start.  I
am running version 7.2.3 in SuSE Linux 7.0 (s390).  I did the build of
postgres on this system.

I had this difficulty when I first installed.  I tried using the startup
script from the contrib directory without any luck.  I put it in the
/etc/rc.d directory and created a symbolic link to it in the rc.2 directory
for starting.  The script works fine if I run it but wouldn't at startup.
So I created my own in the same directory.

#! /bin/sh
case $1 in
  start)
    su -c '/usr/local/pgsql/bin/pg_ctl start -l
/usr/local/pgsql/data/logfile -D /usr/local/pgsql/data' postgres
    ;;
  stop)
    su -c '/usr/local/pgsql/bin/pg_ctl stop -D /usr/local/pgsql/data'
postgres
    ;;
esac

exit 0

This has been working fine for 4 weeks.  Now, all I get at startup is the
message "postmaster successfully started" but I cannot find postmaster
running anywhere in the system.  I know pg_ctl is executing because of the
message but postmaster is not logging anything at all.

I know a little about *nix but not anything about the startup process.  Any
help would be appreciated.

Patrick Bye
Programmer / Analyst
Westfair Foods Ltd.
pbye@westfair.ca
(403) 291-6538