Horizontal scrolling by tilting the mouse wheel is backwards for Microsoft Intellimouse Explorer for Bluetooth. xev reports tilt left as button 7 and tilt right as button 6, but tilting left scrolls right and tilting right scrolls left.
This used to work correctly on oneiric. I'm using Kubuntu, in case it's possible that something in KDE might cause this ;-)
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: xserver-xorg-input-mouse 1:1.7.1-1build3
ProcVersionSignature: Ubuntu 3.2.0-14.23-generic-pae 3.2.3
Uname: Linux 3.2.0-14-generic-pae i686
ApportVersion: 1.91-0ubuntu1
Architecture: i386
Date: Tue Feb 7 15:32:40 2012
ProcEnviron:
LANGUAGE=en_GB
PATH=(custom, user)
LANG=en_GB.UTF-8
SHELL=/bin/bash
SourcePackage: xserver-xorg-input-mouse
UpgradeStatus: Upgraded to precise on 2011-12-09 (60 days ago)
This was filed against the wrong driver package. -mouse is no longer maintained; mice are managed via the -evdev driver and touchpads via -synaptics now.