When I had bought some new waxable fiberglass skiis mine were also very slippery no matter how much I waxed them in all different conditions. I actually would get tired of it and just started skating on my classic skiis. I actually like to skate that way if I'm not on a totally groomed trail - with the classic skiis - then if the trail narrows or I don't have enough oomph to get up a hill I resort to the diagonal stride. It took about a season and a half to get through that to the point where they were not slippery. I actually took a little steel wool to the kicker portion and that helped alot.