si le driver indiqué est PS/2, tu peux essayer de changer le driver souris par :

Section "InputDevice"
Identifier "Mouse2"
Driver "evdev"
Option "bustype" "0x0003"
Option "product" "0xc51a"
Option "relBits" "+0+1+2"
Option "HWheelRelativeAxisButtons" "7 6"
Option "vendor" "0x046d" EndSection