I only see a blue (or green or black) video image most of the time.
You are either watching a very boring video (just kidding) or you are
suffering from a bug in the Xorg 6.7 implementation of X11.
The workaround is to add the line
in the Device section of your X server configuration (usually
/etc/X11/xorg.conf or /etc/X11/XF86Config).