Overtightening the seatpost collar can damage the post. You shouldn't need that much torque (50 inch pounds ought to do) to hold the saddle stable. Sounds like the seatpost is slighly too small (I think Thomson seatposts come in .2mm increments so its easy to have one that looks/feels right when installed but is just a bit too small). Not sure what the seat tube diameter is on a Kilo (26.8, 27, 27.2?) but check that and make sure you have the right size post. If that's right, try replacing the collar.