Alpha issue

I’ve done this a million times and it has always worked:
To create fades- I sometimes use a fade layer that is on top of everything in the movie- that is the same color as the html bg.
This one (for some reason) seems to flicker- indicating that it’s getting darker that 100% for a couple of moments.
Anyone have any idea why- or experienced this before?
After the initial Michelle Tang disappears watch for the flicker in the grey as the (soon to be) home page fades up:
Thanks in advance!