If you bought the bike new before doing anything crazy go to a trek dealer and try and get them to warranty the frame for you. Trek is usually good about standing behind their products and it is not fair to assume the end user will realize their seatpost is not far enough into the frame if they are not above the min insertion line although what FB say's is spot on. Hopefully they will replace the frame for free and try to find a longer post to offer more support, especially since you need a setback post which would put a little more force on the seat tube.