So after posting some messages onto Ellian topic, I was told that the problem came from forge (http://www.minecraftforum.net/topic/193443-v162-ellians-materialdetector-v27/page__st__1760)(See LoRam100 answer at the bottom), and to complain here, which I came to do:
Every time I start the game, the config file isn't detected and I have to re input every of my setting for the Ellian detector mod.
Is there any way to fix this, or any planned update of forge to fix this?
Thanks in advance.