In Ubuntu and its derivative distros there is a common bug with saving settings the brightness of the laptop reboots and returns from sleep mode. My laptop is DNS with Linux Mint Mate and I also saw the following error. However in version 17.1 of such mistakes i did not see again.
Developer Norberthas created a universal script and repository with sysvinit–backlight, which is a problem with the brightness adjustment is solved almost all laptops.
For those who have the problem with the brightness of the laptop, install the script through the terminal.
Installation into Linux Mint 14/15/16/17/17.1: