This is a machining problem IMO. Also, as the riser gets tension on it, say going from 45# to 60# it flexes and opens up the slot. How do I know this? I took the bow apart and the STS rod fit tighter in the slot. I'm sure Martin plans for this but the tolerances must be off on my bow? Also, my string would move off center on my TRG (when I had it) when I would increase poundage as well so I know there is lateral flexing going on.