i don't see that problem with cs6.
i just created a shape with a circular hole and masked a rectangle. i tweened the mask's hole and the tweened mask worked as expected changing the amount of rectangle revealed.
Maybe you can try to save the project and reopen it.
That's true that it worked for me the first time. Not on the second time. I'll try to restart my machine to see what happens.
Anyway, I have a lot of problems with masks. Not only this one.
There is absolutely nothing to correct.... Just to check.
Anyway, I downloaded your file and it doesn't work, as expected.
One thing I didn't really noticed is that it DOES work on publishing (every file : yours, mine) !! It doesn't inside the IDE.... Is this your case ?
But I need to check things inside the IDE. How can we decently work if we have to guess ?
I'm on Flash Version 188.8.131.529 and Mac OS 10.6.8.
it works for me in the ide when testing.
Ok, and what do you have as OS and Flash version ? Are there know issues about some version of Flash ? it could explain a lot of things for me, and maybe correct all these issues....
i've never heard of that issue before and i do quite a lot of reading/answering on the 3 flash forums.
i tested in flash pro cs6 (184.108.40.2069) on a win 7 pro os.
it's possible this is a mac/flash issue. i could test that but i don't have time today.