Hi,
Although the message 'colorspace Grey' works fine for me in PD- extended (version 0.40.3) on Ubuntu Hardy 32 bits, it doesn't work on os X (10.5.6 intel) for me.
I tried pix_film, pix_filmQT, pix_filmDarwin an I got the same thing, even if I load again the same or a new video (something suggested in a message in the Pd window). My videos are RGBA.
loic