Rialto42: use ""Finish Line Fiber Grip"" paste liberally on the seatpost before insertion. It's a gritty paste that greatly increases the coeficient of friction so that carbon fiber components don't slip, even when they're torqued to specifications. Using that paste solved my problems.

I've got both a 20mm layback and an inline version for different saddles/bikes And they have both been easy to adjust, solid and reliable. Have never slipped Either in the frame or in saddle angle. Wouldn't hesitate to get another if either ever breaks.