Dash horizontal icon grid alignment inconsistent

[Alan Pope 🍺🐧🐱 🦄]

The spacing between icons is not consistent between the dash in windowed mode and the dash in full screen mode. Switching between modes causes the icons to "move" a few pixels horizontally. This is more pronounced the larger your screen and the further right you look.

To reproduce. Open a lens with a lot of results. Switch between windowed and fullscreen dash. Observe icons shift left and right as you switch between the two modes.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: unity 6.12.0daily13.01.25-0ubuntu1 [origin: LP-PPA-ubuntu-unity-daily-build]
ProcVersionSignature: Ubuntu 3.8.0-1.5-generic 3.8.0-rc4
Uname: Linux 3.8.0-1-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.8-0ubuntu2
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CrashDB: unity
Date: Fri Jan 25 14:49:22 2013
EcryptfsInUse: Yes
InstallationDate: Installed on 2012-01-02 (388 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120102)
MarkForUpload: True
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)