One last thing !

and the 99-calibration.conf in /etc/X11/xorg.conf.d

Section “InputClass”
Identifier “calibration”
MatchProduct “SMART Technologies Inc. SMART Interactive Whiteboard Controller (SB6) Mouse”
Option “MinX” “121321”
Option “MaxX” “188050”
Option “MinY” “0”
Option “MaxY” “65925”
EndSection

but you can put any values in here and it makes no difference

Ta

Mal