Excuse me, I think I'm having a problem with your brushes. I don't know if it's a version issue or something, but the brushes aren't behaving like I think they should (most of them anyways). The erasers don't erase to white but to the color I have selected in my brush window (had to modify the "eraser" settings in the brush mod window for that). The default radii for the brushes seem to be the same when I drag out the brushes onto the canvas, but when I expand them, they look like a stuttering queue of circles instead of the smooth lines I'm seeing in your demo. Any idea what's going wrong?