8.3.5, can't connect to server (server doesn't listen)

I have two XP laptops connected to each other via cross-over cable. They
ping each other, they connect to each other's drives, no firewalls or
port filter is installed or enabled.

8.3.5 installed on 192.168.10.10
pgAdmin 1.8.4 installed on 192.168.10.12.

Here are the important bits from postgresql.conf and pg_hba.conf:

-- postgresql.conf -- (remainder of file is default with no changes,
including port set to 5432)

#listen_addresses = '*' # what IP address(es) to listen
on;

-- pg_hba.conf -- (remainder of file is default with no changes)

host all all 127.0.0.1/32 md5
host all all 192.168.10.0/24 trust

I have restarted the services after making changes. On client (.12) when
I try to connect to server (.10) via pgAdmin I get "Server doesn't
listen" (and appropriate Guru Hint). On server (.10) Wireshark shows SYN
from 2015 to 5432, then RST, ACK from 5432 to 2015.

I've done a lot of reading in docs and online, including the archives
for this list. I've tried many different options in the two above
mentioned file with no change in results. The settings shown above seem
to be the most viable from all that I've read, but still no dice. I
would appreciate ideas on how to further troubleshot this problem.

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