Hi, firstly thanks Stephen for your help on my zooming problem.
I have one more issue. WHen masking these massive masks I am doing, I sometimes accidentally double-click on a point, which will complete the mask then and there. I have tried to train myself to click more carefully, but it seems to be some sort of automatic desire for feedback if i dont instantly see an edit point appear.
Anyway, some masks are taking me 20 minutes or so, so if i accidentally double click and complete it half way through, ive lost about 10 minutes of work, and i cant seem to undo. If i hit undo, it simply erases the whole mask and i am back to point 1.