Icons in the HUD sometimes don't render quite right

Icons for applications, when shown in the HUD, sometimes don't display right; they get jaggy edges.

An example of where this occurs is when using the HUD with System Settings; see attached screenshots for a comparison.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity 5.4.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-16.25-generic 3.2.6
Uname: Linux 3.2.0-16-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 1.91-0ubuntu1
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,imgpng,move,vpswitch,mousepoll,resize,snap,wall,grid,place,gnomecompat,regex,session,animation,expo,workarounds,fade,ezoom,scale,unityshell]
CompositorRunning: compiz
CurrentDmesg:
 [ 30.434322] [drm] nouveau 0000:00:0d.0: Output VGA-1 is running on CRTC 0 using output A
 [ 32.288431] init: plymouth-stop pre-start process (1460) terminated with status 1
 [ 34.688024] eth0: no IPv6 routers present
Date: Fri Feb 17 18:24:30 2012
DistUpgraded: Log time: 2011-12-07 01:54:25.886125
DistroCodename: precise
DistroVariant: ubuntu
GraphicsCard:
 NVIDIA Corporation C61 [GeForce 6150SE nForce 430] [10de:03d0] (rev a2) (prog-if 00 [VGA controller])
   Subsystem: Giga-byte Technology Device [1458:d000]
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20111129.1)
MachineType: Gigabyte Technology Co., Ltd. M61PME-S2P
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-16-generic root=UUID=2d55fd3e-d932-47b9-abd6-a1fde1ec0453 ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: Upgraded to precise on 2011-12-13 (66 days ago)
dmi.bios.date: 11/03/2009
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: F6
dmi.board.name: M61PME-S2P
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrF6:bd11/03/2009:svnGigabyteTechnologyCo.,Ltd.:pnM61PME-S2P:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnM61PME-S2P:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
dmi.product.name: M61PME-S2P
dmi.sys.vendor: Gigabyte Technology Co., Ltd.
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 2:1.11.4-0ubuntu3
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