evdev touchscreen calibration problems

[Abelenda]

Hi,

I have a little problem calibrating my touchscreen using xinput.

I can invert the Y axis no problem, suppress acceleration, but there is
no way to get calibration right it seems that the numbers I put do not
influence the pointer.

for example I execute :
xinput set-int-prop 6 238 32 500 600 200 300
or
xinput set-int-prop 6 238 32 20 100 30 50

but the cursor is bound in the same rectangle (which is 1/3 of the
total screen size)

xinput list-props 6
shows 

Device 'S3C TouchScreen':
	Device Enabled (112):	1
	Device Accel Profile (231):	-1
	Device Accel Constant Deceleration (232):	1.000000
	Device Accel Adaptive Deceleration (234):	1.000000
	Device Accel Velocity Scaling (235):	10.000000
	Evdev Reopen Attempts (236):	10
	Evdev Axis Inversion (237):	0, 1
	Evdev Axis Calibration (238):	20, 100, 30, 50
	Evdev Axes Swap (239):	0
	Axis Labels (240):	"Abs X", "Abs Y", "Abs Pressure"


Versions:
xf86-input-evdev-2.3.0
xinput-1.5.0 (tested with 1.4.2 didn't change anything)
inputproto-2.0
xorg-server-1.7.4
kernel-2.6.24.7 (heavily patched... but this is the only thing I can't
do anything about)

my log is attached (it doesn't contain anything special though).

Anyone has a pointer if I do something wrong, if evdev can't be used
like this or anything else ?

Because I don't really want to change to tslib+kdrive (as you can't
calibrate tslib from within xorg).
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Xorg.0.log
Type: text/x-log
Size: 8850 bytes
Desc: not available
URL: <http://lists.x.org/archives/xorg/attachments/20100201/05e8bc77/attachment.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: not available
URL: <http://lists.x.org/archives/xorg/attachments/20100201/05e8bc77/attachment.pgp>