sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 1E5F36F0 (this signing key is ONLY for maverick packages. The other ubuntu releases have different signing keys)
2)Afterwards update repositories and install samsung-tools and samsung-backlight: sudo apt-get update sudo apt-get install samsung-tools samsung-backlight
3)Now you have to edit the configuration files: sudo gedit /lib/udev/rules.d/95-keyboard-force-release.rules
Note: in the samsung section you will see a line with *N130*|*N140* etc. add your model number there (don't forget to Save). For example mine is N148 plus but I added |*N148*| and it works.
Also run: sudo gedit /lib/udev/rules.d/95-keymap.rules
Add your model number if it isn't already there (don't forget to Save).