Ubuntu 10.04 - Cannot Create TCP/IP Sockets

Good evening.

I've recently provisioned a new Ubuntu 10.04 server. I ran "apt-get
install postgresql-8.4", just like I normally do when I'm setting up a
new server. However, this time I got an error about an inability to
create TCP/IP sockets. The full error is below.

* Starting PostgreSQL 8.4 database server
* The PostgreSQL server failed to start. Please check the log output:
2010-05-03 03:36:06 UTC LOG: could not bind IPv4 socket: Cannot assign
requested address
2010-05-03 03:36:06 UTC HINT: Is another postmaster already running on
port 5432? If not, wait a few seconds and retry.
2010-05-03 03:36:06 UTC WARNING: could not create listen socket for
"localhost"
2010-05-03 03:36:06 UTC FATAL: could not create any TCP/IP sockets

However, there is nothing on port 5432...

root(at)coolnewserver:~# netstat -l
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 *:ssh *:* LISTEN
tcp 0 0 localhost:smtp *:* LISTEN
tcp6 0 0 [::]:ssh [::]:* LISTEN

...and no postgresql processes...

root(at)coolnewserver:~# ps -ef | grep postgresql
root 7738 3403 0 03:37 pts/0 00:00:00 grep --color=auto postgresql
root(at)coolnewserver:~# ps -ef | grep postmaster
root 7740 3403 0 03:37 pts/0 00:00:00 grep --color=auto postmaster

Possibly pertinent lines from /etc/postgresql/8.4/main/postgresql.conf...

listen_addresses = 'localhost'
port = 5432
max_connections = 100
unix_socket_directory = '/var/run/postgresql'

...permissions on that last directory are...

drwxrwsr-x 2 postgres postgres 40 2010-05-03 03:10 postgresql

...and localhost is resolving...

root(at)coolnewserver:~# nslookup localhost
Server: [IP]
Address: [IP]#53

Name: localhost
Address: 127.0.0.1

Using search engines, I've seen this error, and my question, asked on
occasion; what I didn't find was what the actual solution was. Anyone
remember? I'll be sure to post what I find, so that maybe others can
benefit a few years from now. :)

Thanks...

Daniel