http://bugs.winehq.org/show_bug.cgi?id=18517
--- Comment #25 from phaethon eriks00@moon.lv --- Doing a quick double 'press' (like double click) in the paint area with stylus, selecting menu with a stylus, pressing stylus button or doing something else besides just painting - stops detecting pressure.
I, also, tried patching 1.7.12. It works, but usually stops detecting pressure much earlier even if just painting.