Mouse and pointing stick share pointer speed setting

[wastrel]

The pointing stick on my laptop keyboard shares the pointer speed setting with the external USB mouse, so it's impossible to use both concurrently.

When I undock the laptop I have to change the pointer speed to fast or the pointing stick is unusable.
When I dock the laptop this change must be reversed or the mouse is unusable.

When the laptop is docked, switching between pointing devices is cumbersome as the speed must be changed each time.

There is a separate setting for touchpad, there should be one for the other integrated pointing device.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity 7.2.5+14.04.20150521.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-53.89-generic 3.13.11-ckt19
Uname: Linux 3.13.0-53-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.11
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CurrentDesktop: Unity
Date: Tue Jun 2 11:29:06 2015
InstallationDate: Installed on 2014-02-04 (483 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
SourcePackage: unity
UpgradeStatus: Upgraded to trusty on 2014-06-09 (358 days ago)