Zwar schon ein paar Tage alt, aber evtl hilfts mal jemandem. Planet-X meinte zu meiner bei 5Nm und Carbon Paste rutschenden Stütze:
... Not an uncommon problem...but one that's easily fixed. Take the seat post out of the frame. Thoroughly clean the part of the post that goes in the frame. VERY lightly emery part of the gloss of the part of the post that goes in the frame. VERY lightly..ok? Wipe it clean. Spray it with some of your wife's hairspray (honest)...re-inset it to the required height. Tighten to recommended torque. That'l do the trick ;-)
Regards
XXX