dont use a mask - because masks cant be feathered.....
here's a quick sampe i made:
http://www.mudbubble.com/lab/spotlight_blurred.html here's how i did it:
make a very large rectangle and cut a hole in it (paste a circle in its middle and delete it).
use lasso tool to select area around circle and go to Modify > Shape > Soften Fill Edges.
this will give inner edge of circle a softer feel - make sure you also correct the outer portion of selected area that has also been softened by painting black over it again.
convert this to a symbol and motion tween.
i know my description may be a little sparse - let me know if you need more clarification/detail....
chris georgenes
mudbubble.com
Team Macromedia Volunteer for Flash