Comment 8 for bug 571910

Marques, it looks like you don't actually have gstreamer0.10-ffmpeg installed at all. grepping for ffm should have returned a *lot* of entries if it was installed. I would try to re-install it and see if any errors are thrown. This is also an upstream issue, so if that doesn't fix it please take it up with the GStreamer people, e.g. via IRC in #gstreamer on irc.freenode.org!