Salam Aleikum!
Bem.. a principio não precisei reinstalar o sistema.....
Não consigo precisar qual foi a alteração que resolveu o problema mas foram 4 basicamente.
1 - Li muitos post na net relacionando o problema com "sandy-bridge" especialmente com CPU "Aton", a fui adicionando todos os ppa's e repositórios relacionados.
2 - Habilitei o source dos pacotes "teste" do ubuntu.
3 - Na tela de login optei por usar o Unity 2D ao invés do 3D.
4 - Fiz todas as atualizações disponíveis.
# cat /etc/apt/sources.list
# deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ precise main restricted
# deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/restricted/binary-i386/
# deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/main/binary-i386/
# deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ precise main restricted
# deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/restricted/binary-i386/
# deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/main/binary-i386/
#
# deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/main/binary-i386/
# deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/restricted/binary-i386/
# deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ precise main restricted
# See
http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb
http://br.archive.ubuntu.com/ubuntu/ precise main restricted
deb-src
http://br.archive.ubuntu.com/ubuntu/ precise main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb
http://br.archive.ubuntu.com/ubuntu/ precise-updates main restricted
deb-src
http://br.archive.ubuntu.com/ubuntu/ precise-updates main restricted
## 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://br.archive.ubuntu.com/ubuntu/ precise universe
deb-src
http://br.archive.ubuntu.com/ubuntu/ precise universe
deb
http://br.archive.ubuntu.com/ubuntu/ precise-updates universe
deb-src
http://br.archive.ubuntu.com/ubuntu/ precise-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://br.archive.ubuntu.com/ubuntu/ precise multiverse
deb-src
http://br.archive.ubuntu.com/ubuntu/ precise multiverse
deb
http://br.archive.ubuntu.com/ubuntu/ precise-updates multiverse
deb-src
http://br.archive.ubuntu.com/ubuntu/ precise-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://br.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src
http://br.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse
deb
http://security.ubuntu.com/ubuntu precise-security main restricted
deb-src
http://security.ubuntu.com/ubuntu precise-security main restricted
deb
http://security.ubuntu.com/ubuntu precise-security universe
deb-src
http://security.ubuntu.com/ubuntu precise-security universe
deb
http://security.ubuntu.com/ubuntu precise-security multiverse
deb-src
http://security.ubuntu.com/ubuntu precise-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 precise main
deb-src
http://extras.ubuntu.com/ubuntu precise main
# See
http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
## Major bug fix updates produced after the final release of the
## distribution.
## 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.
## 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.
## 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.
## 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.
###Virtualbox
deb
http://download.virtualbox.org/virtualbox/debian precise contrib
deb
http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu precise main
deb-src
http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu precise main
deb
http://ppa.launchpad.net/glasen/intel-driver/ubuntu precise main
deb-src
http://ppa.launchpad.net/glasen/intel-driver/ubuntu precise main
deb
http://br.archive.ubuntu.com/ubuntu/ precise-proposed restricted main multiverse universe
################################################################################
PPA
###############################################################################
:/etc/apt/sources.list.d# ls
glasen-intel-driver-precise.list medibuntu.list.save sarvatt-intel-sna-precise.list tualatrix-ppa-precise.list.save
glasen-intel-driver-precise.list.save myunity-ppa-precise.list sarvatt-intel-sna-precise.list.save ubuntu-wine-ppa-precise.list
libreoffice-ppa-precise.list myunity-ppa-precise.list.save shnatsel-zram-precise.list ubuntu-wine-ppa-precise.list.save
libreoffice-ppa-precise.list.save precise-partner.list shnatsel-zram-precise.list.save xorg-edgers-ppa-precise.list
medibuntu.list precise-partner.list.save tualatrix-ppa-precise.list xorg-edgers-ppa-precise.list.save
Não tenho certeza do que vou falar, mas estava desesperado não contava com tempo hábil para formatar e fazer backup... Então "fiz de tudo", se alguém tiver este problema e quiser testar o simples ato de usar o Unity 2D rebootar e por novamente o 3D, pra fins de teste......
Então meu problema esta solucionado...... Mais alguém quer discutir sobre isso??