Alright, I tried:
_quality = "BEST";
In the first frame, AND I tried changing to pngs, but not working.
I did figure out that when I put those alpha transparencies BENEATH the text, you don't get that corruption. When I put one cloud layer above the text, you get the corruption.
The corruption does not happen to regular bitmaps or vector graphics, it only happens to vector/bitmap graphics that are symbols. What a bunch of crap
I'm gonna have to call macromedia and work around this one...