HELP... Wierd Masking Problem

OK… this problem is so totally wierd that i’m not even going to try to explain it.

i’ve attached a little fla which contains the problem.

i have a text box which i want to be slowly revealed by a mask layer. i’ve set the whole thing up as you would expect.

when i preview the effect in Flash it works perfectly - like a dream. But…

when i “Test Movie” (or publish) IT TOTALLY DOESN’T WORK AT ALL… YOU CAN’T SEE A THING! NO TEXT BOX, NO MASK, NOTHING!!!

somebody please help me before i go completely nuts.