The machine is running an nvidia optimus hardware, that is Intel + nVidia. Bumblebee is installed on the machine, and works when used, but I don't use it.
As per https://wiki.ubuntu.com/X/Troubleshooting/Freeze > Problem: Freeze began after a system update No kernel package update near the time of bug appearance. $ zgrep -h " installed linux-image" /var/log/dpkg.log* | sed 's/^[^:]*://' | sort2012-04-19 07:40:25 status installed linux-image-3.2.0-23-generic 3.2.0-23.36 2012-04-19 07:40:25 status installed linux-image-generic 3.2.0.23.25 2012-04-27 12:15:45 status installed linux-image-3.2.0-24-generic 3.2.0-24.37 2012-04-27 12:15:50 status installed linux-image-generic 3.2.0.24.26 2012-05-22 00:23:58 status installed linux-image-3.2.0-24-generic 3.2.0-24.38 2012-05-24 09:33:37 status installed linux-image-3.2.0-24-generic 3.2.0-24.39 2012-06-14 15:53:31 status installed linux-image-3.2.0-25-generic 3.2.0-25.40 2012-06-14 15:53:31 status installed linux-image-generic 3.2.0.25.27 Bug observed after upgrading, but I did not use external monitor every day, so I'm not sure which update triggered the problem, but this may hint : $ zgrep " installed xserver-xorg-video-intel" /var/log/dpkg.log* | sed 's/^[^:]*://' | sort 2012-04-19 07:43:06 status installed xserver-xorg-video-intel 2:2.17.0-1ubuntu4 2012-05-02 14:47:10 status installed xserver-xorg-video-intel 2:2.18.0-1ubuntu1~xup1 2012-05-03 09:18:32 status installed xserver-xorg-video-intel 2:2.19.0-0ubuntu1~xup1 $ zgrep " installed xserver-xorg-core" /var/log/dpkg.log* | sed 's/^[^:]*://' | sort 2012-04-19 07:43:06 status installed xserver-xorg-core 2:1.11.4-0ubuntu10 2012-05-02 14:47:07 status installed xserver-xorg-core 2:1.11.4-0ubuntu10.1 2012-06-02 22:38:11 status installed xserver-xorg-core 2:1.11.4-0ubuntu10.2 I had enabled X Updates as part of investigating #987056 "Suspend always hangs on Asus N55S, becomes really hot " I may try enabling/disabling https://launchpad.net/~ubuntu-x-swat/+archive/x-updates and/or https://launchpad.net/~xorg-edgers/+archive/ppa At the moment they have default ubuntu 12.04: xserver-xorg-video-intel 2:2.17.0-1ubuntu4 X Updates: xserver-xorg-video-intel 2:2.19.0-0ubuntu1~xup1 xorg-edgers: xserver-xorg-video-intel 2:2.19.0+git20120626.a072ab50-0ubuntu0sarvatt -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-intel in Ubuntu. https://bugs.launchpad.net/bugs/1002542 Title: Xorg freeze within weeks, but within minutes after plugging external monitor. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1002542/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp
