You can stretch a 34.9mm to be a 35.6mm, and you can squish a 35.6mm to be a 34.9mm. I'm not sure which one of you is using the "right" size, but hey, if it holds your seatpost in place...
that's realy odd since i always run a 34.9mm all the time and you run a 35.6mm,since the seat tube is the same diameter on our frames for all frame sizes.