Version:            (using KDE KDE 3.1.4)
Installed from:    SuSE RPMs
OS:          Linux

The mouse mapping (left-handed) is applied only to the
first/core mouse. The first mouse is ps/2, the second
one (which map incorrectly) is a usb mouse.

.kde/share/config/kcminputrc
============================
[Mouse]
Acceleration=3
MouseButtonMapping=LeftHanded


XF86Config
==========
Section "InputDevice"
  Driver       "mouse"
  Identifier   "Mouse[0]"
  Option       "ButtonNumber" "5"
  Option       "Device" "/dev/mouse"
  Option       "Name" "Autodetection"
  Option       "Protocol" "imps/2"
  Option       "Vendor" "Sysp"
  Option       "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
  Driver       "mouse"
  Identifier   "Mouse[1]"
  Option       "ButtonNumber" "5"
  Option       "Device" "/dev/usbmouse"
  Option       "Name" "Autodetection"
  Option       "Protocol" "imps/2"
  Option       "Vendor" "Sysp"
  Option       "ZAxisMapping" "4 5"
EndSection

Section "ServerLayout"
  Identifier   "Layout[all]"
  InputDevice  "Keyboard[0]" "CoreKeyboard"
  InputDevice  "Mouse[0]" "CorePointer"
  InputDevice  "Mouse[1]" "SendCoreEvents"
...