Turn off PRESSURE. It's the Green glowing toggle next to individual pressures on the brush gui, the last little toggle before the border of the window. If you have that turned off, your rotation will follow your brush direction!

(But then size and opacity dynamics will respond to movement speed. Turn those off, too!

)
I should add, though, that this is not as cool in this version than what I've already got for the new one. In the new one this stuff is all a bit different and MUCH nicer, including the routine to determine the direction for the brush. SO...it's a poor patch right now, but- just so you know- I've had that all along for a long time, just as long as I've had size or opacity controlled by movement speed!
