**Using Wacom Cintiq 15x in ubuntu 12.04**
for some reason if screen is rotated, twinview (separate x instances for each screen) will not work.
when using 2 screens and no twinview, xinput_calibrator will not work correctly
identify the device id: xinput --list | grep stylus
identify the property to set: xinput list-props $id | grep Wacom\ Tablet\ Area
to rotate: xinput list-props $id | grep Rotation
for a rotation to the left set rotation to 2
calibrating with rotation 2: xinput -set-prop id prop y-top x-right y-bottom x-left
  * lower numbers for x move to left
  * lower numbers for y move down 
  * example xinput -set-prop 10 273 60 -1475 6496 16000