Pressure not working on Surface

[jjbat]

Hi,
I was looking to buy paintstorm studio, so I downloaded the trial. Problem is I can't get pressure sensitivty to work.
I think I've tried everything suggested in previous threads.
I've updated my Surface, installed all the drivers, Installed the Wintab drivers, disabled touch and flick gesture, uninstalled and installed paintstorm studio, run the compatibility tool, rebooted various times, but I still can't get it to work.
Am I missing something?

[support]

you can also try to delete wintab driver.