I seem to encounter a problem when I use the brush tool that occassionally it seems to switch to a different tool. I don't know if anyone else has this problem but sometimes it forgets that I am using the brush end and acts like an eraser, or it sticks to the last tool I used.
I did try to dupe your problem, but was unsuccessful. I wonder if your stylus might need to be replaced?
I doubt it, because I remember this being a problem in past versions of painter. I encounter the same problem on different tablets which use different styli.
Arshes, do you frequently flip your stylus when working? The problem as you describe it never happens to me but then again I very rarely use the eraser end.
Yes, I do use flip the stylus to erase.
I don't get the brushes shifting either.... but I never flip the pen to use the eraser.