Postgres 8.4 on OpenIndiana would not shutdown

Hello listmates,

When I run the following:

postgres(at)zeus:~$ export PGDATA=/var/postgres/8.4/data_64/

postgres(at)zeus:~$ /usr/postgres/8.4/bin/amd64/pg_ctl stop

waiting for server to shut
down............................................................... failed
pg_ctl: server does not shut down
postgres(at)zeus:~$ /usr/postgres/8.4/bin/amd64/pg_ctl stop

waiting for server to shut
down............................................................... failed
pg_ctl: server does not shut down
postgres(at)zeus:~$

The Postgres 8.4 would simply not shutdown for me. Don't know why:

Here's a snippet of /var/postgres/8.4/data_64/server.log seemingly
corresponding to these shutdown attempts:

LOG: database system was shut down at 2012-10-25 13:49:14 EDT
LOG: database system is ready to accept connections
LOG: autovacuum launcher started
LOG: received smart shutdown request
LOG: autovacuum launcher shutting down
LOG: shutting down
LOG: database system is shut down
LOG: database system was shut down at 2012-10-26 12:14:21 EDT
LOG: autovacuum launcher started
LOG: database system is ready to accept connections
LOG: received smart shutdown request
LOG: autovacuum launcher shutting down
LOG: shutting down
LOG: database system is shut down
LOG: database system was shut down at 2012-10-26 12:22:00 EDT
LOG: database system is ready to accept connections
LOG: autovacuum launcher started

Would anybody know what's wrong with this picture? And how to fix it?

Thanks.

Boris.