Interesting; few people confirm in bug 840683 that the dimming doesn't occur at all. The bug's description and second comment suggest that the 'dim on idle and on power' option isn't even coded or at least its description is misleading. What graphic card do you use? I recommend you to follow that bug report too. Feel free to continue to report any other bugs you may find.
** Summary changed: - [Oneiric] Dim on idle does not brighten with activity + Dim on idle does not brighten with activity -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-power-manager in Ubuntu. https://bugs.launchpad.net/bugs/844241 Title: Dim on idle does not brighten with activity Status in “gnome-power-manager” package in Ubuntu: New Bug description: I've upgraded my laptop from natty to oneiric and I've noticed that when I leave the pc idle (or I manually lock the screen) the back-light is not restored when I move the mouse or press a key, but I must turn it on and increase it using the keyboard button. Is the same behaviour described in this old bug #199522. Naturally if I uncheck the option "dim screen to save power" the issue doesn't occur. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-power-manager/+bug/844241/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp