xrandr and dvi output

[Gerfried Fuchs <rhonda@deb.at>]

	Hi!

 I recently got an external monitor that has DVI input. Was quite nice,
before I only had an VGA screen. Though, the VGA screen worked
perfectly: I was able to enable the external monitor at any time with
xrandr, enabling it, disabling it, whatever.

 With the DVI screen I now have the problem that xrandr is able to
detect it, but not really enable it. Well, it /claims/ that it enables
it, growing the screen layout to the appropriate size, but it doesn't
display anything. It only works after a fresh reboot when the external
monitor was plugged. After a suspend of the system and awaking it again
the external monitor isn't possible to get any output anymore.

 Does this sound familiar to anyone? Does anyone what might be the
problem with sleep mode here, not able to turn on DVI output properly
anymore?

 Any hints more than welcome, thanks in advance!
Rhonda