[Lenovo T540p] Lock hotkey does not work on this system with 12.04.5

CID: 201309-14211 Lenovo T540p

The "Lock" key on this system does not work

sudo showkey -s shows:
0xe0 0x5b 0x26 0xa6 0xe0 0xdb

sudo showkey -k shows:
keycode 125 press
keycode 38 press
keycode 38 release
keycode 125 release

xev shows:
FocusOut event, serial 36, synthetic NO, window 0x4000001,
    mode NotifyGrab, detail NotifyAncestor

FocusIn event, serial 36, synthetic NO, window 0x4000001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 36, synthetic NO, window 0x0,
    keys: 4294967231 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
           32 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

KeyPress event, serial 36, synthetic NO, window 0x4000001,
    root 0xbf, subw 0x0, time 86088642, (-364,162), root:(731,214),
    state 0x10, keycode 133 (keysym 0xffeb, Super_L), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

FocusOut event, serial 36, synthetic NO, window 0x4000001,
    mode NotifyGrab, detail NotifyAncestor

FocusIn event, serial 36, synthetic NO, window 0x4000001,
    mode NotifyUngrab, detail NotifyAncestor

KeymapNotify event, serial 36, synthetic NO, window 0x0,
    keys: 2 0 0 0 0 64 0 0 0 0 0 0 0 0 0 0
           32 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

KeyRelease event, serial 36, synthetic NO, window 0x4000001,
    root 0xbf, subw 0x0, time 86088642, (-364,162), root:(731,214),
    state 0x50, keycode 46 (keysym 0x6c, l), same_screen YES,
    XLookupString gives 1 bytes: (6c) "l"
    XFilterEvent returns: False

KeyRelease event, serial 36, synthetic NO, window 0x4000001,
    root 0xbf, subw 0x0, time 86088643, (-364,162), root:(731,214),
    state 0x50, keycode 133 (keysym 0xffeb, Super_L), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False

Basically it's the combination of Left super + l, but it won't lock the screen in 12.04.5

You could find this key next to the calculator key in the upper right corner:
http://imagizer.imageshack.us/a/img823/8710/wqpu.jpg

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.13.0-32-generic 3.13.0-32.57~precise1 [modified: boot/vmlinuz-3.13.0-32-generic]
ProcVersionSignature: Ubuntu 3.13.0-32.57~precise1-generic 3.13.11.4
Uname: Linux 3.13.0-32-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version k3.13.0-32-generic.
ApportVersion: 2.0.1-0ubuntu17.7
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 1: PCH [HDA Intel PCH], device 0: ALC292 Analog [ALC292 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: ubuntu 1906 F.... pulseaudio
 /dev/snd/controlC0: ubuntu 1906 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'HDMI'/'HDA Intel HDMI at 0xf2630000 irq 48'
   Mixer name : 'Intel Haswell HDMI'
   Components : 'HDA:80862807,80860101,00100000'
   Controls : 21
   Simple ctrls : 3
Card1.Amixer.info:
 Card hw:1 'PCH'/'HDA Intel PCH at 0xf2634000 irq 49'
   Mixer name : 'Realtek ALC292'
   Components : 'HDA:10ec0292,17aa2210,00100001'
   Controls : 22
   Simple ctrls : 10
Card29.Amixer.info:
 Card hw:29 'ThinkPadEC'/'ThinkPad Console Audio Control at EC reg 0x30, fw unknown'
   Mixer name : 'ThinkPad EC (unknown)'
   Components : ''
   Controls : 1
   Simple ctrls : 1
Card29.Amixer.values:
 Simple mixer control 'Console',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Date: Thu Sep 18 03:10:53 2014
HibernationDevice: RESUME=UUID=b8c8ba7e-fe13-498a-a864-e61be51434c8
InstallationMedia: Ubuntu 12.04.5 LTS "Precise Pangolin" - Release amd64 (20140807.1)
MachineType: LENOVO 20BFZ052US
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-32-generic root=UUID=93b275d1-0513-474e-bbad-07e19aeaaac8 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-32-generic N/A
 linux-backports-modules-3.13.0-32-generic N/A
 linux-firmware 1.79.16
SourcePackage: linux-lts-trusty
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/20/2014
dmi.bios.vendor: LENOVO
dmi.bios.version: GMET62N1 (2.10 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20BFZ052US
dmi.board.vendor: LENOVO
dmi.board.version: Win8 Pro DPK TPG
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrGMET62N1(2.10):bd03/20/2014:svnLENOVO:pn20BFZ052US:pvrThinkPadT540p:rvnLENOVO:rn20BFZ052US:rvrWin8ProDPKTPG:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 20BFZ052US
dmi.product.version: ThinkPad T540p
dmi.sys.vendor: LENOVO