user-changed brightness settings do not survive re-boot

Most of Ubuntu's System Settings survive re-boot, but changing the screen brightness does not.
This is annoying to me because every time I boot up I must lower the settings manually.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: compiz 1:0.9.9~daily13.03.08-0ubuntu1
ProcVersionSignature: Ubuntu 3.8.0-13.22-generic 3.8.3
Uname: Linux 3.8.0-13-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.9.1-0ubuntu1
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
Date: Mon Mar 18 15:40:27 2013
DistUpgraded: Fresh install
DistroCodename: raring
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:2203]
InstallationDate: Installed on 2013-01-04 (73 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130102)
MachineType: LENOVO 3434CTO
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-13-generic root=UUID=95a4680b-da7a-4fce-b22e-ab8fe87eb927 ro quiet splash vt.handoff=7
SourcePackage: compiz
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/25/2012
dmi.bios.vendor: LENOVO
dmi.bios.version: GCET21WW (1.10 )
dmi.board.asset.tag: Not Available
dmi.board.name: 3434CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Defined
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrGCET21WW(1.10):bd07/25/2012:svnLENOVO:pn3434CTO:pvrThinkPadX230Tablet:rvnLENOVO:rn3434CTO:rvrNotDefined:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 3434CTO
dmi.product.version: ThinkPad X230 Tablet
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.9~daily13.03.08-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.42-0ubuntu2
version.libgl1-mesa-dri: libgl1-mesa-dri 9.0.3-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 9.0.3-0ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.13.3-0ubuntu2b1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.3-0ubuntu2b2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.1.0-0ubuntu1b1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.21.4-0ubuntu1b1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.6-0ubuntu3b1
xserver.bootTime: Mon Mar 18 15:30:40 2013
xserver.configfile: default
xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.13.3-0ubuntu2b1
xserver.video_driver: intel