why does "vbetool dpms off" work and "xset dpms *" not?

[Bastian Venthur <expires-2006@venthur.de>]

Hi devels,

I'm trying to get my backlight powered off in order to save power. It does
currently not work on console or X.

At least on console I found out, that 
        vbetool dpms off|on
works to power off|on the backlight.

Sadly 
        xset dpms suspend|standby 
does not, so my console is not able to shut down the backlight after some
time if inactivity.

First question: What does vbetool, what xset can't do?
And my second question: If this is a bug of xset, who can I contact in order
to get this fixed?

BTW: I've played with gentoo a few months ago and powering off the backlight
after 20mins of inactivity worked out-of-the box while still compiling the
kernel for the first reboot. As far as I remember gentoo did not use some
special boot parameters.
 

Kind regards

Bastian