Comment 3 for bug 631412

This is not on kubuntu only - I have exactly the same problem on Ubuntu. My laptop is not the same as the reporter's (it's a Samsung R430), but it has the same graphics chipset, has the same backlight setting problem, I've used the same workaround on Lucid, and now it also doesn't work on Maverick. I my case, taking off only "nomodeset" from the kernel options allows the system to boot into X, and though the brightness does change accordingly when the system is running on AC or battery (whereas without "acpi_backlight=vendor" not even that happens), the brightness can no longer me set on the Power Management on Gnome Preferences (the slider is missing).