I have a problem with my almost new (2 months old) Salomon fsk 237 blade. The second axle continuosly unscrews itself. I've changed axles, bearings, wheels, but no change. That one just don't want to stay put, so it's a problem with the joint. Is there some kind of product which can "lock" the joint better? Is this a common problem with the Salomon fsk blades? You can answer me in French.

Have you tried some "thread glue" (called "frein filet" in French)? A common brand around here is Loctite...