Using kubuntu 6.10 on amd64 and using proprietary nvidia drivers I have a problem where my monitor flickers on and off. It calms down when I restrict the monitor in xorg.conf to 60 on vert. refresh and 28-64 on horiz, but theres still flickers every so often, and they can build up to the point where there is no picture for a while. Switching to a low res console always fixes it, and sometimes just leaving kde, going to the kdm will fix it... :/ im using a dell 1907fp on the digital input. I thought that possibly adding the display size to xorg.conf might help more, or a slight change in horiz refresh, but im not sure what to set these to.