Your problem is similar to the guy with the linolium flooring. (follow link) Have you checked the floor with a damp meter, or do you know that the floor and walls are moisture tight. Have they been reproofed recently? If your not sure then you will need to waterproof the floor first using something like Synthaproof, then I would line the floor with somthing in the order of Marine ply, treating it where ever you cut it (edges etc). Finally laying your floor on top of it, oh you may want to provide a styrine insulation layer between the concrete floor and the next layer you fix, as it will cut down the cold on the floor and allow the timbers to breath slightly.