I use a multihead system and when I watch a video I can only use one monitor at a time. When I place the video window (doesn't matter if it's VLC, totem or mplayer) on the ridge between the monitors the image gets cut in half and blanks on one of the monitors. When I move the window to the second monitor completely it shows the video regularly. Now when I start a video, place it on the secondary display and start the first one again I can use both monitors to display it. The video simply spans across the ridge and is displayed on the second screen. I can only have videos span both screens when there are multiple video instances active. I use ATi fglrx Catalyst 7.12 drivers (8.443) on a Ubuntu Gutsy 7.10 system.
I just noticed that the video does NOT blank on the second monitor if the window is not focused. If I bring the video instance in front again, one half goes black as before. I use the Xubuntu flavor of Ubuntu with xfce4's xf4wm window manager.
GStreamer's bugzilla is at http://bugzilla.gnome.org/
This entry in FDO's bugzilla is strictly for administrative requests related to accounts.
Please refile the bug there.