Just tried Ubuntu 12.04.2 and the the same problem occurs there, though in 12.04 this issue was non existent.
** Changed in: xorg (Ubuntu) Status: New => Confirmed -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1069064 Title: Screen keeps blinking after boot up Status in “xorg” package in Ubuntu: Confirmed Bug description: Hi, I tried installing ubuntu quantal on my acer 5002 laptop with sis card. But on boot from usb screen keeps flickering with only mouse pointer shows up on whole screen. I tried xubuntu as well and result is same. --- ApportVersion: 2.0.1-0ubuntu14 Architecture: i386 DistroCodename: precise DistroRelease: Ubuntu 12.04 DistroVariant: ubuntu InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423) Package: xorg 1:7.6+12ubuntu1 PackageArchitecture: i386 ProcEnviron: LANGUAGE=en_IN:en TERM=xterm PATH=(custom, no user) LANG=en_IN SHELL=/bin/bash ProcVersionSignature: Ubuntu 3.2.0-32.51-generic-pae 3.2.30 Tags: precise ubuntu Uname: Linux 3.2.0-32-generic-pae i686 UnreportableReason: Please work this issue through technical support channels first. UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1069064/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp