hi and thanks digman,
i listed the version above as 4.7.24 and was actually just using the grow brush. i most definitely did not use surface brushes since they are way down the menu and i was playing around with the "topshelf" brushes. still, your comments did help, thank you.
tbh i think it must have been a bug because i actually did not have that happen again.
btw workflow wise - i suppose it does not make sense to switch from voxel to surface very often right, due to detail loss? apparently voxel is good for sketching where surface is for refining and finalising. i´d be very interested to hear pros and cons of each within 3dcoat.
i actually much prefer working in voxel space but am not sure if this is the way to go. retopo, detailing and projection would be then handled in zbrush, since i am more comfortable with it atm.