I have a dual screen setup using xrandr and the nouveau driver. I have gnome compiled with the xinerama flag and other full screen video is correctly confined to one screen.
When I open a full screen youtube video, swfdec tries to center the video in the center of my two screens. So, the left side of my main monitor is just black, and the right side of my main monitor shows the left half of the video. Nothing is displayed on my second monitor (which is correct behavior).
Swfdec should center the video at the center my main screen not the center of my combined screens.
Created attachment 17903 [details]
Full screen youtube. My main mointor is on the left.
Added a screenshot for clarification.
Yup, known problem.
It's mainly unfixed because I don't have a Xinerama setup to test with.
*** This bug has been marked as a duplicate of bug 16530 ***