I have Ubuntu Lucid with kernel 2.6.35 on a Thinkpad T61. In the power management settings I set it up to blank the display after 2 minutes. This works right after I log in, but after a few hours of active use, closing applications and then walking away from the computer, the display won't ever blank until I log out and log in again. The screensaver, although enabled, activates only in the first few hours after logging in.
What can be the root cause of the problem?
Incorrect screensaver or blanking settings cannot be the root cause, because these features work with the current settings right after logging in.
User-visible applications (such as Firefox, Chrome, their Flash player or Skype) cannot be the root cause, because the screen doesn't blank even after I quit these. (Verified with
Is there a workaround?
How do I debug the problem? Is there a tool which displays a counter like 1:57 seconds until blanking?
Please note that in this question I don't care about sleep, suspend or hibernate -- I care only about blanking the display.