It certainly sounds like you're not a novice at this. Neither am I, but sometimes we just run into a rough one like this. I'll have to do some thinking.
I can say that I have a 2008 FireCat and a 2009 Moab. I have worked religiously with the FireCat and shoot a bare shaft out to 30 years like it's attached to a laser. At 40 yards it shows a little nock low, but sometimes it's time to stop tinkering as one of my friends keep saying. Yeah, right.
The Moab on the other hand is just downright stubborn. I do need to work with it more, but there's no way it's going to bare shaft the same arrows at the same poundage. I mean, so far it's not even close.
Just for info are you using a loop or shooting off the string?
If You're Not Living on the Edge You're Taking Up Too Much Space
Martin/Rytera Staff Shooter
PSAA Life member, UBP Life member
PADI AOW Diver