Problem with pressure

I have a Wacom Sapphire, and 2 of my friends have a Wacom Bamboo Fun, and we can’t use the “stylet mode” (with pressure) with the brush and the eraser.
We tested with others Wacom tablet and it works, whereas them, when they use ours, it doesn’t work.
I read that all wacom tablet is compatible with Toon Boom, so I don’t know where is the problem.

Thanks for your answers.

have you tried updating your tablet drivers from the wacom site, restarting the computer, deleting your pen tablet preferences with the tablet’s utility tool on your computer…