I've heard of this before, but I think I remember hearing problems occurred when switching to 2.4 from 72 MgHZ.

If my memory serves me correctly, I think the problem turned out to be uncurable, but, I can't even remember this post as I write it! Ha!

HSR has a new valve that replaces the EVSD. I have 4 of those valves working liking a champ after years of abuse. I love them in air models.