PostgreSQL server listen on other port than 5432

Hi.

I'm using CentOS 5.3 and PostgreSQL version 8.1.11.

I opened the posgres SQL to accept incoming connections:

<snip start from postgresql.conf>
listen_addresses = '*'
# comma-separated list of addresses;
# defaults to 'localhost', '*' = all
port = 5432
max_connections = 100
<snip end>

It seems that the posgres SQL sometimes listen on other ports than 5432:
# lsof -i -n -P | grep postg
postmaste 18415 postgres 3u IPv4 99670 TCP *:17583 (LISTEN)
postmaste 18415 postgres 4u IPv6 102029 TCP *:5432 (LISTEN)
postmaste 18415 postgres 5u IPv4 102030 TCP *:5432 (LISTEN)
postmaste 18415 postgres 8u IPv4 102038 UDP
127.0.0.1:53420->127.0.0.1:53420
postmaste 18421 postgres 3u IPv4 99670 TCP *:17583 (LISTEN)
postmaste 18423 postgres 3u IPv4 99670 TCP *:17583 (LISTEN)
postmaste 18423 postgres 8u IPv4 102038 UDP
127.0.0.1:53420->127.0.0.1:53420
postmaste 18424 postgres 3u IPv4 99670 TCP *:17583 (LISTEN)
postmaste 18424 postgres 8u IPv4 102038 UDP
127.0.0.1:53420->127.0.0.1:53420
postmaste 18425 postgres 3u IPv4 99670 TCP *:17583 (LISTEN)
postmaste 22242 postgres 3u IPv4 99670 TCP *:17583 (LISTEN)
postmaste 22242 postgres 8u IPv4 102038 UDP
127.0.0.1:53420->127.0.0.1:53420
postmaste 22242 postgres 9u IPv4 117409 TCP
127.0.0.1:5432->127.0.0.1:55254 (ESTABLISHED)
postmaste 22270 postgres 3u IPv4 99670 TCP *:17583 (LISTEN)
postmaste 22270 postgres 8u IPv4 102038 UDP
127.0.0.1:53420->127.0.0.1:53420
postmaste 22270 postgres 9u IPv4 117489 TCP
127.0.0.1:5432->127.0.0.1:55256 (ESTABLISHED)

The extra port which is being used (17583) is a port that i need to
other services.
Did anyone see this issue?

Thanks
Dotan