Comment 9 for bug 257377

Ahh so, after spending weeks,months,years.... trying to figure this out
it ended up being a simple fix:(remember once hotplugging is disable, you need xorg.conf).

Section "ServerFlags"
     Option "AutoAddDevices" "False"
EndSection

the cause is the removal of evdev:

cat /var/log/Xorg.0.log
(II) config/hal: Adding input device applesmc
(**) applesmc: always reports core events
(**) applesmc: Device: "/dev/input/event8"
(II) applesmc: Found x and y absolute axes
(WW) applesmc: Don't know how to use device
(II) UnloadModule: "evdev" <----ignoreABI seemed to not work for me
(EE) PreInit returned NULL for "applesmc"
(EE) config/hal: NewInputDeviceRequest failed

Now to see how to have hotplugging and Xorg know what to do with applesmc:
maybe some kind of eye candy mechanism!!