Thank you for your bug report, those log seems to indicate you are having issue with xorg or nouveau (the nvidia driver):
Feb 6 19:52:00 g4 kernel: [ 3719.559347] LR [e9dbc308] nouveau_wait_eq+0x80/0xc4 [nouveau] Feb 6 19:52:00 g4 kernel: [ 3719.559354] Call Trace: Feb 6 19:52:00 g4 kernel: [ 3719.559368] [df061a40] [e5f00000] 0xe5f00000 (unreliable) Feb 6 19:52:00 g4 kernel: [ 3719.559398] [df061a50] [e9dbc308] nouveau_wait_eq+0x80/0xc4 [nouveau] Feb 6 19:52:00 g4 kernel: [ 3719.559433] [df061a80] [e9dc9798] nv_load_state_ext+0x8e4/0xf04 [nouveau] Feb 6 19:52:00 g4 kernel: [ 3719.559464] [df061ad0] [e9dcf260] nouveau_hw_load_state+0xb8/0x14c [nouveau] Feb 6 19:52:00 g4 kernel: [ 3719.559538] [df061af0] [e9e2d2b8] nv_crtc_commit+0x44/0x1a8 [nouveau] Feb 6 19:52:00 g4 kernel: [ 3719.559563] [df061b20] [e9a98410] drm_crtc_helper_set_mode+0x238/0x38c [drm_kms_helper] Feb 6 19:52:00 g4 kernel: [ 3719.559577] [df061d10] [e9a98dbc] drm_crtc_helper_set_config+0x6dc/0x974 [drm_kms_helper] Feb 6 19:52:00 g4 kernel: [ 3719.559675] [df061d90] [e9a0efe0] drm_mode_setcrtc+0x2f0/0x38c [drm] Feb 6 19:52:00 g4 kernel: [ 3719.559700] [df061e10] [e99fe3fc] drm_ioctl+0x1d4/0x44c [drm] Feb 6 19:52:00 g4 kernel: [ 3719.559713] [df061ee0] [c01648f4] do_vfs_ioctl+0xac/0x348 Feb 6 19:52:00 g4 kernel: [ 3719.559722] [df061f10] [c0164c1c] sys_ioctl+0x8c/0xac Feb 6 19:52:00 g4 kernel: [ 3719.559733] [df061f40] [c001876c] ret_from_syscall+0x0/0x38 Feb 6 19:52:00 g4 kernel: [ 3719.559747] --- Exception: c01 at 0x20268ca0 ** Package changed: lightdm (Ubuntu) => xorg-server (Ubuntu) -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/920131 Title: Machine locks up when logging out from Desktop Status in “xorg-server” package in Ubuntu: New Bug description: When I log out from LXDE or XFCE using the logout-shutdown button in the taskbar, the logout takes a very long time during which the machine is frozen. Not even existing ssh sessions work. I'd expect the logout to take a few seconds, rather than a few minutes, and I would expect to be able to continue to use ssh while the logout is occuring in the GUI. ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: lxde (not installed) ProcVersionSignature: Ubuntu 3.2.0-10.17-powerpc 3.2.1 Uname: Linux 3.2.0-10-powerpc ppc ApportVersion: 1.91-0ubuntu1 Architecture: powerpc Date: Sun Jan 22 21:19:43 2012 InstallationMedia: Lubuntu 12.04 "Precise Pangolin" - Alpha powerpc (20120119) ProcEnviron: LANGUAGE=en_US:en PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: lxde-common UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/920131/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

