Comment 1 for bug 83965

Looks like the problem comes from this (from console output) :

First instance:
video_out_xv: using Xv port 73 from adaptor ATI Radeon Video Overlay for hardware colorspace conversion and scaling.

Second instance:
video_out_xv: Xv extension is present but I couldn't find a usable yuv12 port.
              Looks like your graphics hardware driver doesn't support Xv?!

Here is my devide section in xorg.conf:
Section "Device"
        Identifier "ATI Technologies, Inc. Radeon X600 (RV380)"
        Driver "ati"
        BusID "PCI:3:0:0"
        Option "DRI" "true"
        Option "ColorTiling" "on"
        Option "EnablePageFlip" "true"
        Option "AccelMethod" "EXA"
        Option "XAANoOffscreenPixmaps"
        Option "RenderAccel" "true"
        Option "AGPFastWrite" "on"
EndSection