I just installed a new Easton EC90 fork that uses their new Easton headset adjuster. This device sits between the stem and headset and expands to tighten the headset. Problem is that it won't stay tight. I assume my stem is migrating up the carbon steer tube and loses the tension. I am afraid to tighten the stem any more and crush the steer tube. Anyone else have this problem or have a solution? Should I just use an expansion plug instead of or in addition to the head set adjuster? Are their certain stems that work better with carbon steer tubes than others?

Thanks for any advice!