BUG #9416: Setting up postgresql-9.1 (9.1.12-0wheezy1) Fails Configuration

The following bug has been logged on the website:

Bug reference: 9416
Logged by: Patrick Boake
Email address: pboake(at)gmail(dot)com
PostgreSQL version: 9.1.12
Operating system: Debian
Description:

I have seen multiple reports of this but no solutions beyond 'whitelisting'
the package in update-rc.d.

I don't know how to do that or why it's necessary.

No other problems with system.

apt-get upgrade returns;

Setting up postgresql-9.1 (9.1.12-0wheezy1) ...
[....] Starting PostgreSQL 9.1 database server: main[....] The PostgreSQL
server failed to start. Please check the log output: 2014-03-02 22:13:28 EST
LOG: could not bind IPv4 socket: Cannot assign requested address 2014-03-02
22:13:28 EST HINT: Is another postmaster already running on port 5432? If
not, wait a few seconds and retry. 2014-03-02 22:13:28 EST LOG: could not
bind IPv6 socket: Cannot assign requested address 2014-03-02 22:13:28 EST
HINT: Is another postmaster already running on port 5432? If not, wait a few
seconds and retry. 2014-03-02 22:1[FAILEST WARNING: could not create listen
socket for "localhost" 2014-03-02 22:13:28 EST FATAL: could not create any
TCP/IP sockets ... failed!
failed!
invoke-rc.d: initscript postgresql, action "start" failed.
dpkg: error processing postgresql-9.1 (--configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
postgresql-9.1
E: Sub-process /usr/bin/dpkg returned an error code (1)