Comment 11 for bug 954661

Mario, from your comment #5, it sounds to me like the problem may be due to there being two /sys/class/backlight interfaces present (acpi_video0 and intel_backlight). Mario & Daniel, you might try booting with the kernel boot parameter "acpi_backlight=vendor" which should disable acpi_video0 leaving only intel_backlight. Does that improve any of the behaviors you're seeing (or make them worse)?