Hey thank you for your answer.
So like I said, yes, it is when I plug or unplug "something" from my computer.
It happens to me just now, coz I'm under LM since now more than 3 months but 2 or 3 weeks ago this happened. I think it is due to one of my updates. I usually update my computer each month.
It happens when I plug a pen drive, but also when I insert a CD, or remove my battery.
I guess my kernel has something to do with it.
However I'm not at all an expert, I can be considered as a Newbie, so I need to be driven if there are different solutions.
If anyone can help me it will be great.
PS: Husse, nothing related to the topic, but I'm in Erasmus exchange at this moment and I'm in Sweden man, precisely in Halmstad. That's really a beautiful country. I'm from France and it is unbelievable how it is totally different between Latin and Scandinavian countries. That's great!