Comment 8 for bug 26709

does it bleed to any particular colour?

the problem I was seeing was that the colourkey was black, so anything black
occupying the same co-ordinates on-screen as the video, regardless of whether
the video was behind it or not, was painted with the video. unfortunately the
only machine I have access to now has an intel chipset in it, else I'd look further.

so, for instance, try starting a black terminal or something, then opening a
white editor, say. if it narrows to a particular colour, then good, that's just
a busted colourkey. if not, there are deeper issues at play.