RE: Tuning problems / ????'s
Before I spent oney on anyhing,I would check the arrows at 60#'s.That is what the chart I have from Easton says you need.At that point,if the spine is the problem,then the 340's would be fine at 65#'s.
Arthur is right about the strings and cables,good chance they need to be adjusted and may be the source of the problem.