I'm running Ubuntu 12.04 with the latest updates on my Dell Latitude E6410 with the latest BIOS and the screen doesn't power down (it does blank but backlight stays on) after the defined timeout set like it used to be in the previous versions.

This is the exact same issue as described here: http://ubuntuforums.org/showthread.php?t=1954960 but there's no solution & the thread is locked.