Looking at your list of installed packages there are still quite a few Xorg packages from PPAs installed.
xserver-xorg-video-s3 1:0.6.5+git20120912.92d10d5d-0ubuntu0sarvatt 0 xserver-xorg-video-savage 1:2.3.6+git20120801.3d181030-0ubuntu0sarvatt 0 xserver-xorg-video-siliconmotion 1:1.7.7+git20120801.2beb25bd-0ubuntu0sarvatt 0 xserver-xorg-video-sis 1:0.10.7+git20120912.339fb3bc-0ubuntu0sarvatt 0 xserver-xorg-video-sisusb 1:0.9.6+git20120801.894814fe-0ubuntu0sarvatt 0 xserver-xorg-video-tdfx 1:1.4.5-0ubuntu1 0 xserver-xorg-video-trident 1:1.3.6+git20120801.3098fe71-0ubuntu0sarvatt 0 xserver-xorg-video-vesa 1:2.3.2+git20120912.7aafaf56-0ubuntu0sarvatt 0 xserver-xorg-video-vmware 1:12.0.2+git.e5ac80d8-0ubuntu1 0 The PPA needs to be enabled for PPA purge to revert back to the old packages and then uninstall them, so you may need to reenable it first in software-properties-gtk. You can use the command 'apt-cache policy xserver-xorg-video-trident' to determine where the xserver-xorg-video- trident came from. Good luck! -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1247656 Title: Fails to calculate upgrade setting software channels with custom ppas purged To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1247656/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs