Paintstormstudio.com

I just bought the program, and from the start I have no pressure with my pen. Im using the GT 191 with the newest drivers (they are like 3months old). I tryed playing around with the driver, but the only effect it had, was that it didnt pick up my pen at all when i turned off "game accelerate". Windows Ink didnt seem to change anything.
Pls Help. I really want to use this Program over free Programs, but like this its kinda impossible.
Attatchment is a screenshot of hard and light pressure strokes (both pretty slow strokes)