Chuck,
Sounds like you have the expereince in boats so its probobly not your abilities The Guillmot has to real pronounced skegs for and aft as part of the bow stern design. So I'm pretty sure its not the design. with my own I found I had to take a Japanese rasp to the skegs to get less go straight out of my boat.

I have a guess. We have seen this before on this board. Not sure who it was but a few months back we saw this a few times before. The issue was the seat. After going through all the possibilites building a real tight seat that trasfers your hip moveemnts directly to the hul made the difference. Any one remeber whose boat that was?

Any case try padding outthe seat al lthe way up. I'm guessing she'll come true on ya. and feel like a different boat

Godd luck

!RUSS