My Ubuntu 12.10 Desktop installation keeps display's backlight on when running screensaver. I'm talking about the whatever screensaved comes by default.
My power setting is set to turn off displays after 5 minutes of inactivity. What happens instead is black screen with background light on. Sometimes, displays will power off for some time and then turn back on.
I've tried using
xset dpms force off command to manually turn monitors off and it works for maybe few minutes/hours (I'm not sure exactly how long it stays off because I do that before I go to sleep and wake up in the middle of the night with displays lighting up my room).
Locking my account doesn't help to fix this either. Sometimes screensaver won't even start at all and I find my computer unlocked and fully on when I come back from work.
I have my .xsession-errors log file right here, in case that helps. Are there any other logs that could shed some light on what's happening?
I'm running Unity, on nvidia GTX460 with 310-experimental (same was happening with the default "stable" version), two 24" LCDs. This is a relatively fresh install, about month old, installed on a new partition (no upgrades). Previously I was running 12.04 and saw exactly the same thing happening.