At fullscreen mode, pointer behaves very erratically with multitouch screen & Wacon pen. Using external mouse it works however properly.
In windowed mode touchscreen works properly.
Likely reason for problem is that touchscreen & pen return absolute coordinates, which are not handled correctly when in fullscreen mode.
I also noticed a slight gameplay issue with touchscreen - as it's not very accurate pointing device, it is extremely hard to click to the edge of the window.
Suitable behaviour could be that when clicking border, it would be interpreted as clicking at nearest window edge.
ScummVM version 1.4.1.
Linux (ubuntu 12.04 64-bit)
Hardware Samsung 7 Slate, w/ Atmel maXTouch touchscreen & Wacom v4 pen.