Off-Topic??? <Fn>-<F4>, internal/external monitor switch-functionality on laptop

[David Wiedemann]

Hi

I have a question and am a bit lost, as I also don't get a hint in the 
internet. Would be great, if anybody could give me an idea how to proceed...

I have SuSE Professional 9.1 with XFree 4.3.99 on my laptop, a compaq 
Armada M700.

I'm very fine (especially as with XFCE it is nice fast :-) ), but I 
cannot use the external port. When I press <Fn>-<F4> which is suposed to 
switch between the internal LCD and the external graphic-port, my 
picture is for a short time moving, but nothing happens. When I have an 
external monitor attached, nothing happens at all. There had somebody 
else also that problem:
    http://www.linuxforums.org/forum/topic-23169.html
I have no idea, where to begin with my search...

If anybody has an idea, I would be very greatfull for a hint, thank you!
David