@Bryce, downgrading the whole system doesn't help, either. So maybe it's caused by a removed or newly installed package or configuration file. $ dpkg -l "*udev*" | grep ^.i ii libgudev-1.0-0 1:167-0ubuntu3 GObject-based wrapper library for libudev ii libgudev1.0-cil 0.1-2 GObject-based wrapper library for libudev -- CLI bindings ii libudev0 167-0ubuntu3 udev library ii system-config-printer-udev 1.3.1+20110222-0ubuntu16.4 Printer auto-configuration facility based on udev ii udev 167-0ubuntu3 rule-based device node and kernel event manager $ dpkg -l "*xorg*" | grep ^.i ii xorg 1:7.6+4ubuntu3.1 X.Org X Window System ii xorg-docs-core 1:1.5.99.901-1ubuntu1 Core documentation for the X.org X Window System ii xserver-xorg 1:7.6+4ubuntu3.1 the X.Org X server ii xserver-xorg-core 2:1.10.1-1ubuntu1.1 Xorg X server - core server ii xserver-xorg-input-all 1:7.6+4ubuntu3.1 the X.Org X server -- input driver metapackage ii xserver-xorg-input-evdev 1:2.6.0-1ubuntu12 X.Org X server -- evdev input driver ii xserver-xorg-input-kbd 1:1.5.0+git20110108.849f5092-0ubuntu2 X.Org X server -- keyboard input driver ii xserver-xorg-input-mouse 1:1.6.0-1ubuntu3 X.Org X server -- mouse input driver ii xserver-xorg-input-synaptics 1.3.99+git20110116.0e27ce3a-0ubuntu12.1 Synaptics TouchPad driver for X.Org server ii xserver-xorg-input-vmmouse 1:12.6.99.901-1ubuntu2 X.Org X server -- VMMouse input driver to use with VMWare ii xserver-xorg-input-wacom 1:0.10.11-0ubuntu4 X.Org X server -- Wacom input driver ii xserver-xorg-video-all 1:7.6+4ubuntu3.1 the X.Org X server -- output driver metapackage ii xserver-xorg-video-apm 1:1.2.3-0ubuntu5 X.Org X server -- APM display driver ii xserver-xorg-video-ark 1:0.7.3-1ubuntu3 X.Org X server -- ark display driver ii xserver-xorg-video-ati 1:6.14.0-0ubuntu4.1 X.Org X server -- AMD/ATI display driver wrapper ii xserver-xorg-video-chips 1:1.2.3-2ubuntu5 X.Org X server -- Chips display driver ii xserver-xorg-video-cirrus 1:1.3.2-2ubuntu7 X.Org X server -- Cirrus display driver ii xserver-xorg-video-fbdev 1:0.4.2-3ubuntu6 X.Org X server -- fbdev display driver ii xserver-xorg-video-i128 1:1.3.4-1ubuntu3 X.Org X server -- i128 display driver ii xserver-xorg-video-intel 2:2.14.0-4ubuntu7.1 X.Org X server -- Intel i8xx, i9xx display driver ii xserver-xorg-video-mach64 6.8.2+git20101202.d60087f0-4ubuntu3 X.Org X server -- ATI Mach64 display driver ii xserver-xorg-video-mga 1:1.4.13.dfsg-3build1 X.Org X server -- MGA display driver ii xserver-xorg-video-neomagic 1:1.2.5-1ubuntu3 X.Org X server -- Neomagic display driver ii xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu7 X.Org X server -- Nouveau display driver (experimental) ii xserver-xorg-video-openchrome 1:0.2.904+svn916-1build1 X.Org X server -- VIA display driver ii xserver-xorg-video-qxl 0.0.12-1ubuntu4 X.Org X server -- QXL display driver ii xserver-xorg-video-r128 6.8.1-4ubuntu3 X.Org X server -- ATI r128 display driver ii xserver-xorg-video-radeon 1:6.14.0-0ubuntu4.1 X.Org X server -- AMD/ATI Radeon display driver ii xserver-xorg-video-rendition 1:4.2.4-0ubuntu5 X.Org X server -- Rendition display driver ii xserver-xorg-video-s3 1:0.6.3-3ubuntu3 X.Org X server -- legacy S3 display driver ii xserver-xorg-video-s3virge 1:1.10.4-3ubuntu3 X.Org X server -- S3 ViRGE display driver ii xserver-xorg-video-savage 1:2.3.2-3ubuntu2 X.Org X server -- Savage display driver ii xserver-xorg-video-siliconmotion 1:1.7.4-0ubuntu7 X.Org X server -- SiliconMotion display driver ii xserver-xorg-video-sis 1:0.10.3-2ubuntu3 X.Org X server -- SiS display driver ii xserver-xorg-video-sisusb 1:0.9.4-0ubuntu5 X.Org X server -- SiS USB display driver ii xserver-xorg-video-tdfx 1:1.4.3-3ubuntu3 X.Org X server -- tdfx display driver ii xserver-xorg-video-trident 1:1.3.4-0ubuntu5 X.Org X server -- Trident display driver ii xserver-xorg-video-tseng 1:1.2.4-0ubuntu5 X.Org X server -- Tseng display driver ii xserver-xorg-video-vesa 1:2.3.0-4ubuntu3 X.Org X server -- VESA display driver ii xserver-xorg-video-vmware 1:11.0.3-1ubuntu3 X.Org X server -- VMware display driver ii xserver-xorg-video-voodoo 1:1.2.4-0ubuntu5 X.Org X server -- Voodoo display driver The installed version of xserver-xorg-core is 2:1.10.1-1ubuntu1.1, not 2:1.10.2-1ubuntu1. $ uname -srvmpio Linux 2.6.38-10-generic #46-Ubuntu SMP Tue Jun 28 15:07:17 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux $ cd /dev/input; for i in event*; do echo $i:; /lib/udev/input_id /class/input/$i; done event0: ID_INPUT=1 event1: ID_INPUT=1 ID_INPUT_KEY=1 event2: ID_INPUT=1 ID_INPUT_KEY=1 event3: ID_INPUT=1 ID_INPUT_KEY=1 ID_INPUT_KEYBOARD=1 event4: ID_INPUT=1 ID_INPUT_KEY=1 event5: ID_INPUT=1 ID_INPUT_KEY=1 event6: ID_INPUT=1 ID_INPUT_TOUCHPAD=1 event7: ID_INPUT=1 ID_INPUT_KEY=1 event8: ID_INPUT=1 ID_INPUT_MOUSE=1 event9: ID_INPUT=1 ID_INPUT_MOUSE=1 $ sudo X -verbose 99 2>&1 | grep input/event (II) config/udev: ignoring device /dev/input/event2 without property ID_INPUT set (II) config/udev: ignoring device /dev/input/event4 without property ID_INPUT set (II) config/udev: ignoring device /dev/input/event0 without property ID_INPUT set (II) config/udev: ignoring device /dev/input/event1 without property ID_INPUT set (II) config/udev: ignoring device /dev/input/event9 without property ID_INPUT set (II) config/udev: ignoring device /dev/input/event5 without property ID_INPUT set (II) config/udev: ignoring device /dev/input/event3 without property ID_INPUT set (II) config/udev: ignoring device /dev/input/event6 without property ID_INPUT set (II) config/udev: ignoring device /dev/input/event8 without property ID_INPUT set (II) config/udev: ignoring device /dev/input/event7 without property ID_INPUT set