Crash on Tweening a TextField with a mask AS3 CS3

Question

I have yet to hunt down exactly what it is about this
situation that makes it crash, but when I tween the position of a
TextField that has a mask, as soon as I close the movie window the
program crashes, whether it be in the Flash (CS3) IDE or in a
browser.
In detail: I have a movie where I'm creating 1000 instances
of a movieclip (little dots) and when the mouse rolls over one i
instantiate another movieclip, call it box. I then dynamically
create a textfield inside the box and give it a mask (a generated
sprite that is just a rectangle half the width of the box, which is
added to the box's display list). Finally, I tween the x position
of the TextField, giving the effect of the text sliding out from
the edge of the box. When I test the movie in Flash this works fine
but as soon as I close the window Flash crashes, in a browser
window when I close the window I get the spinning beach ball of
death. If I dont add a mask to the TextField, I dont have this
problem at all. I will test this on a PC tomorrow, but as of yet
can only confirm on a Mac.
Has anyone ever encountered something like this?
I dont have the code in front of me, but it is really what
youd imagine, along the lines of (NOTE: this is not my exact
code):

Answer 1

I have the same problem in version CS6. I assume Adobe hasn't done anything about it?