Why is this simple, masked animation flickering?

Question

I'm working on animating a pie chart. I've started with a hypothetical 60% chunk. Here's the fla... it's pretty simple, but in order to mask more than 180 degrees I had to use a movie clip for a mask, which seems to work fine but for one small thing... no matter how many timelines I put a stop action on, I get a repeating flicker that looks like looping to me at the end.

I've got a stop at the end of every timeline involved – even single-frame ones. I've put a trace on all these as well to make sure they're being hit, and they are.

Maybe my brain fell out, but I can see no earthly reason for the flicker on the swf upon export. I suspect the cause is simple, and am prepared to feel like an idiot (too late). Please, experts, tell me what is up here!

https://www.dropbox.com/s/k0a7u5x7vu6yh8l/chart-animations-working.fla.zip?dl=0

EDIT: Here is a link to the swf:

http://ilium.com/test/chart-animations-working.html

Answer 1

Your movie clip 'piechartmask1' has a blank keyframe at the end of its timeline, and that's why it is disappearing (flickering out). You could shorten the symbol to be only a single frame in duration; it would then not need an actions layer or a stop command and would persist indefinitely.