postmaster, but not pg_ctl -i -i

I'm having an odd problem where I can start up postmaster just fine with
the following command:

$ /usr/local/pgsql/bin/postmaster -D .
DEBUG: database system was shut down at 2002-11-14 05:04:25 EST
DEBUG: checkpoint record is at 0/115894
DEBUG: redo record is at 0/115894; undo record is at 0/0; shutdown TRUE
DEBUG: next transaction id: 91; next oid: 16556
DEBUG: database system is ready

This also works fine if I do a pg_ctl without using the "-o -i" option, I
get the same.

No, I stop the postmaster that's running, do a 'ps -ef', and make sure NO
postmasters are running. Then, I execute:

$ pg_ctl -D . stop
pg_ctl: cannot find ./postmaster.pid
Is postmaster running?

$ pg_ctl start -D . -o -i
postmaster successfully started
FATAL: StreamServerPort: bind() failed: Address already in use
Is another postmaster already running on port 5432?
If not, wait a few seconds and retry.
/usr/local/pgsql/bin/postmaster: cannot create INET stream port

BUT, if I do:

$ postmaster -D . -o -i -p 5432
DEBUG: database system was shut down at 2002-11-14 05:35:49 EST
DEBUG: checkpoint record is at 0/115954
DEBUG: redo record is at 0/115954; undo record is at 0/0; shutdown TRUE
DEBUG: next transaction id: 91; next oid: 16556
DEBUG: database system is ready

Why is this happening? Why is pg_ctl behaving differently when I specify
"-o -i"? If I run pg_ctl without the -o -i options, it runs fine, so I'm
pretty sure that that's it. Also, I don't think it's a port issue,
otherwise postmaster would have the same problem on the 5432.

This issue was posted at:

http://archives.postgresql.org/pgsql-admin/1998-11/msg00044.php

And I checked my /tmp dir, but there's nothing there.

Any thoughts?

Thanks in Advance,
Aurangzeb