I normally set the screen to go blank after N seconds, but after using the machine for a while, it stops working mysteriously. It may be due to the suspend event.
Now I try:
xset s 2
and the screen won't blank after 2 (or more) seconds.
But this succeeds to blank the screen:
sleep 2; xset s activate
so it implies the blank screen function itself is normal.
Also, this prints the idle time correctly:
sleep 10; xprintidle
so it implies X is getting the idle time correctly.
I have removed xfce4-power-manager (and also exited the current process).
I'm not sure how to reproduce this, but it happens almost surely when I have my machine on for a long time (perhaps with suspension).
I will try to see if the first suspension is causing the problem.
