Video is not showing

[Pierre Hansson]

Hi everyone!

I got a little problem that I haven't had before.

I have a laptop sitting in it's dock, attached to it there's a monitor, 
keyboard etc. The problem is when playing videofiles or watching tv
then the attached monitor doesn't show any video, but it does show on
the laptop itself. 
It has worked before, but now, suddenly it doesn't, does anyone have a clue?

Everything else show up fine, everything but video, all I get is black where 
the video is supposed to show up, and In all programs, well, things like 
YouTube and stuff works.

Any help is appreciated.