Comment 3 for bug 66646

Alright, so, to resume what can be found in the Xorg.0.log (because I'd say the problem is not from X) :
(II) LoadModule: "wacom"
(II) Loading /usr/lib/xorg/modules/input//wacom_drv.so
(II) Module wacom: vendor="X.Org Foundation"
        compiled for 4.3.99.902, module version = 1.0.0
        Module class: X.Org XInput Driver
        ABI class: X.Org XInput driver, version 0.7
(II) Wacom driver level: 47-0.7.7-7 $
[...]
(**) stylus: always reports core events
(**) stylus device is /dev/wacom
(**) stylus is in absolute mode
(**) stylus: forcing TabletPC ISD V4 protocol
(**) WACOM: suppress value is 2
(**) Option "BaudRate" "9600"
(**) stylus: serial speed 9600
(**) Option "SendCoreEvents"
(**) cursor: always reports core events
(**) cursor device is /dev/wacom
(**) cursor is in relative mode
(**) cursor: forcing TabletPC ISD V4 protocol
(**) WACOM: suppress value is 2
(**) Option "BaudRate" "9600"
(**) cursor: serial speed 9600
(**) Option "SendCoreEvents"
(**) eraser: always reports core events
(**) eraser device is /dev/wacom
(**) eraser is in absolute mode
(**) eraser: forcing TabletPC ISD V4 protocol
(**) WACOM: suppress value is 2
(**) Option "BaudRate" "9600"
(**) eraser: serial speed 9600
[...]
(II) XINPUT: Adding extended input device "Synaptics Touchpad" (type: MOUSE)
(II) XINPUT: Adding extended input device "eraser" (type: Wacom Eraser)
(II) XINPUT: Adding extended input device "cursor" (type: Wacom Cursor)
(II) XINPUT: Adding extended input device "stylus" (type: Wacom Stylus)
(II) XINPUT: Adding extended input device "Configured Mouse" (type: MOUSE)
(II) XINPUT: Adding extended input device "Generic Keyboard" (type: KEYBOARD)
(**) Option "Device" "/dev/wacom"
Wacom xf86WcmWrite error : Input/output error
(**) Option "Device" "/dev/wacom"
Wacom xf86WcmWrite error : Input/output error
(**) Option "Device" "/dev/wacom"
Wacom xf86WcmWrite error : Input/output error

more interesting info :
$ dmesg | grep wac
[ 24.432000] usbcore: registered new interface driver wacom
[ 24.432000] drivers/usb/input/wacom_sys.c: v1.46:USB Wacom Graphire and Wacom Intuos tablet driver

$ ls -l /etc/wacom
lrwxrwxrwx 1 root root 10 2007-04-21 10:29 wacom -> /dev/ttyS0

$ cat /dev/wacom
cat: /dev/wacom: Aucun périphérique de ce type (Means "no peripheral of this type/kind")
$ cat /dev/ttyS0
cat: /dev/ttyS0: Aucun périphérique de ce type

$ ls /sys/bus/pnp/devices/ | gawk '{ print "cat "$0"/id"}' | sh
PNP0c01
PNP0a03
PNP0200
PNP0800
PNP0c04
TOS7406
PNP0303
PNP0f13
PNP0b00
PNP0c02
WACf004
SMCf030

$ cat /sys/bus/pnp/devices/00:09/id
WACf004
$ ls /sys/bus/pnp/devices/00:09
bus driver id options power resources subsystem tty:ttyS0 uevent

The device is detected by the kernel, but somehow, it doesn't get bound to ttyS0 ?
I don't get what happening here