Ive always used the proprietary driver in Ubuntu.
with the Catalyst 9.xx Drivers i had to run:
sudo aticonfig --set-pcs-str="DDX,EnableRandr12,FALSE" in a terminal to stop the flicker.
With the 10.xx Drivers though this has no effect.
Anyone any ideas how I can stop this annoying flicker?

ps. Using the HD2400 Driver on a 1680x1050 monitor