When i embbed flash movies within websites i can set the background to transparency, thus the website background shines through.
That leds me to the thought, that flash-movies must have transparent backgrounds (if released right?!).
I would like to use that in resolume!
(I know that AlphaTransparency combined with recoloring of the flashmovie works - but it has ugly artefacts on all borders and produces sometimes even errors.)