I updated my evdev driver to the latest in CVS. The wheels on mice will get
detected properly now. However they are mapped in the wrong way. The wheel up
event is mapped to button 4 correctly but for some reason the wheel down event
gets mapped to button 49.

I can fix this by doing xmodmap -e "pointer = 1 2 3 4 5"

here's the output from Xorg.log and xev:

(EE) Keyboard1: name: (null), phys: isa0060/serio0/input0, device: (null).
(II) evdev brain: Rescanning devices (1).
(**) Option "CoreKeyboard"
(**) Keyboard1-isa0060/serio0/input0: Core Keyboard
(**) Keyboard1-isa0060/serio0/input0: XkbRules: "xorg"
(**) Option "XkbModel" "evdev"
(**) Keyboard1-isa0060/serio0/input0: XkbModel: "evdev"
(**) Option "XkbLayout" "us"
(**) Keyboard1-isa0060/serio0/input0: XkbLayout: "us"
(**) Option "XkbOptions" "grp:alt_shift_toggle,grp_led:scroll,compose:rwin"
(**) Keyboard1-isa0060/serio0/input0: XkbOptions:
"grp:alt_shift_toggle,grp_led:scroll,compose:rwin"
(EE) mouse1: name: (null), phys: isa0060/serio1/input0, device: (null).
(II) evdev brain: Rescanning devices (2).
(II) evdev brain: AT Translated Set 2 keyboard 2 -> AT Translated Set 2 keyboard 1.
(**) Option "CorePointer"
(**) mouse1-isa0060/serio1/input0: Core Pointer
(II) mouse1-isa0060/serio1/input0: Found 3 relative axes.
(II) mouse1-isa0060/serio1/input0: Configuring as pointer.
(**) mouse1-isa0060/serio1/input0: WHEELRelativeAxisButtons: 4 5.
(II) mouse1-isa0060/serio1/input0: Found 3 mouse buttons
(II) mouse1-isa0060/serio1/input0: Configured 5 mouse buttons
(II) XINPUT: Adding extended input device "mouse1-isa0060/serio1/input0" (type:
MOUSE)
(II) XINPUT: Adding extended input device "Keyboard1-isa0060/serio0/input0"
(type: KEYBOARD)
(II) XINPUT: Adding extended input device "evdev brain" (type: evdev brain)
(II) XINPUT: Adding extended input device "NVIDIA Event Handler" (type: Other)
(II) Keyboard1-isa0060/serio0/input0: Init
(EE) evdev_btn.c (95): Registering 5 buttons.
(II) mouse1-isa0060/serio1/input0: Init
(II) evdev brain: Rescanning devices (3).
(II) evdev brain: AT Translated Set 2 keyboard 3 -> AT Translated Set 2 keyboard 2.
(II) evdev brain: ImPS/2 Logitech Wheel Mouse 3 -> ImPS/2 Logitech Wheel Mouse 2.
(II) Keyboard1-isa0060/serio0/input0: On
(II) mouse1-isa0060/serio1/input0: On


MotionNotify event, serial 26, synthetic NO, window 0x3800001,
    root 0x7f, subw 0x3800002, time 506174, (43,34), root:(55,111),
    state 0x10, is_hint 0, same_screen YES

ButtonPress event, serial 26, synthetic NO, window 0x3800001,
    root 0x7f, subw 0x3800002, time 507087, (43,34), root:(55,111),
    state 0x10, button 4, same_screen YES

EnterNotify event, serial 26, synthetic NO, window 0x3800001,
    root 0x7f, subw 0x0, time 507087, (43,34), root:(55,111),
    mode NotifyGrab, detail NotifyInferior, same_screen YES,
    focus YES, state 2064

KeymapNotify event, serial 26, synthetic NO, window 0x0,
    keys:  127 0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
           0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0

ButtonRelease event, serial 26, synthetic NO, window 0x3800001,
    root 0x7f, subw 0x3800002, time 507087, (43,34), root:(55,111),
    state 0x810, button 4, same_screen YES

LeaveNotify event, serial 26, synthetic NO, window 0x3800001,
    root 0x7f, subw 0x0, time 507087, (43,34), root:(55,111),
    mode NotifyUngrab, detail NotifyInferior, same_screen YES,
    focus YES, state 16

ButtonPress event, serial 26, synthetic NO, window 0x3800001,
    root 0x7f, subw 0x3800002, time 507888, (43,34), root:(55,111),
    state 0x10, button 49, same_screen YES

EnterNotify event, serial 26, synthetic NO, window 0x3800001,
    root 0x7f, subw 0x0, time 507888, (43,34), root:(55,111),
    mode NotifyGrab, detail NotifyInferior, same_screen YES,
    focus YES, state 16

KeymapNotify event, serial 26, synthetic NO, window 0x0,
    keys:  127 0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
           0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0

ButtonRelease event, serial 26, synthetic NO, window 0x3800001,
    root 0x7f, subw 0x3800002, time 507888, (43,34), root:(55,111),
    state 0x10, button 49, same_screen YES

LeaveNotify event, serial 26, synthetic NO, window 0x3800001,
    root 0x7f, subw 0x0, time 507888, (43,34), root:(55,111),
    mode NotifyUngrab, detail NotifyInferior, same_screen YES,
    focus YES, state 16