This question is a followup for this [one].1
I've identified the problem as being related to different xorg driver versions. My /etc/apt/sources.list file on the upgraded system is as follows:
# deb cdrom:[Ubuntu 12.04.2 LTS _Precise Pangolin_ - Release amd64 (20130213)]/ dists/precise/main/binary-i386/
# deb cdrom:[Ubuntu 12.04.2 LTS _Precise Pangolin_ - Release amd64 (20130213)]/ dists/precise/restricted/binary-i386/
# deb cdrom:[Ubuntu 12.04.2 LTS _Precise Pangolin_ - Release amd64 (20130213)]/ precise main restricted
deb-src http://archive.ubuntu.com/ubuntu trusty main restricted #Added by software-properties
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://archive.ubuntu.com/ubuntu trusty main restricted
deb-src http://archive.ubuntu.com/ubuntu trusty multiverse universe #Added by software-properties
## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu trusty-updates main restricted
deb-src http://archive.ubuntu.com/ubuntu trusty-updates restricted main multiverse universe #Added by software-properties
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu trusty universe
deb http://archive.ubuntu.com/ubuntu trusty-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://archive.ubuntu.com/ubuntu trusty multiverse
deb http://archive.ubuntu.com/ubuntu trusty-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu trusty-backports main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu trusty-backports main restricted universe multiverse #Added by software-properties
deb http://archive.ubuntu.com/ubuntu trusty-security main restricted
deb-src http://archive.ubuntu.com/ubuntu trusty-security restricted main multiverse universe #Added by software-properties
deb http://archive.ubuntu.com/ubuntu trusty-security universe
deb http://archive.ubuntu.com/ubuntu trusty-security multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu precise partner
# deb-src http://archive.canonical.com/ubuntu precise partner
## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu trusty main
deb-src http://extras.ubuntu.com/ubuntu trusty main
This is the same file used for 12.04. I've replaced it with:
deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-security main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-updates main restricted universe multiverse
###### Ubuntu Extras Repo
deb http://extras.ubuntu.com/ubuntu trusty main
##############################################################
##################### UNOFFICIAL REPOS ######################
##############################################################
###### 3rd Party Binary Repos
#### LibreOffice PPA - http://www.documentfoundation.org/download/
## Run this command: sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 1378B444
deb http://ppa.launchpad.net/libreoffice/ppa/ubuntu trusty main
#### Tor: anonymity online - http://www.torproject.org/
## Run this command: gpg --keyserver subkeys.pgp.net --recv 886DDD89 && gpg --export --armor 886DDD89 | sudo apt-key add -
deb http://deb.torproject.org/torproject.org trusty main
#### X Updates PPA - https://launchpad.net/~ubuntu-x-swat/+archive/x-updates/
## Run this command: sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys AF1CDFA9
deb http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu trusty main
####### 3rd Party Source Repos
#### LibreOffice PPA (Source) - http://www.documentfoundation.org/download/
## Run this command: sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 1378B444
deb-src http://ppa.launchpad.net/libreoffice/ppa/ubuntu trusty main
#### Tor: anonymity online (Source) - http://www.torproject.org/
## Run this command: gpg --keyserver subkeys.pgp.net --recv 886DDD89 && gpg --export --armor 886DDD89 | sudo apt-key add -
deb-src http://deb.torproject.org/torproject.org trusty main
#### X Updates PPA (Source) - https://launchpad.net/~ubuntu-x-swat/+archive/x-updates/
## Run this command: sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys AF1CDFA9
deb-src http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu trusty main
I am now unable to reinstall the xserver-xorg package(package xserver-xorg has no installation candidate). May someone please post the contents of the sources.list files on an Ubuntu 14.04.01 workstation with a functional xserver package?