When switching application tabs (with Alt+1..9 shortcuts) the HUD sometimes shows up

I use the Alt+1...9 shortcuts to switch application tabs (gnome-terminal, chromium, firefox, etc) all the time, and quite often the HUD shows up after the tab is switched. This doesn't happen if I press the Alt key, followed by the number and then release Alt, but I frequently seem to release the Alt key at almost the same time I press the number and that's when the HUD shows up. I thought this could be the same cause as bug 923410 or bug 937036 but those seem to happen consistently, regardless of how fast you release the Alt key.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity 5.4.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-17.26-generic 3.2.6
Uname: Linux 3.2.0-17-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 1.92-0ubuntu1
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,decor,regex,gnomecompat,vpswitch,compiztoolbox,move,resize,grid,animation,snap,imgpng,place,session,mousepoll,workarounds,wall,expo,fade,ezoom,scale,unityshell]
CompositorRunning: compiz
Date: Wed Feb 22 11:29:58 2012
DistUpgraded: Log time: 2012-01-16 19:12:13.495938
DistroCodename: precise
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0126] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:21d2]
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
MachineType: LENOVO 4170CTO
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-17-generic root=UUID=6c8b89f7-f0ef-440b-bea8-ccb5f8d5b8a3 ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: Upgraded to precise on 2012-01-17 (36 days ago)
dmi.bios.date: 11/01/2011
dmi.bios.vendor: LENOVO
dmi.bios.version: 8CET50WW (1.30 )
dmi.board.asset.tag: Not Available
dmi.board.name: 4170CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr8CET50WW(1.30):bd11/01/2011:svnLENOVO:pn4170CTO:pvrThinkPadT420s:rvnLENOVO:rn4170CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 4170CTO
dmi.product.version: ThinkPad T420s
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.7.0~bzr2995-0ubuntu4
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.30-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0~rc2-0ubuntu5
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0~rc2-0ubuntu5
version.xserver-xorg-core: xserver-xorg-core 2:1.11.4-0ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.99.901+git20120126-0ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20111219.aacbd629-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.17.0-1ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20111201+b5534a1-1build2