I have a problem with my seatpost slipping down. The bike is carbon with a carbon post. The post looks like there may be an aluminum insert, but I don't want to tighten any harder then I have already for fear of crushing the post. My thoughts are to replace the seatpost with a Thompson Elite, and then upgrading the collar to a Salsa Lip-Lock. I was hoping that might fix the problem, but was hoping for some input here.