over the combination of in-mast furling and Bergstrom & Ridder rig.
The B&R rig is designed to support itself without a backstay. It's also designed to carry a considerable bend. This is all well and good if you want a deep-roach, full-battened mainsail (except it will lie against the swept-back spreaders when you try to run downwind with it).
A boat I was supposed to review had in-mast furling in a B&R mast. I knew from past experience (and the manuals) that in-mast furling does not work if there is any bend in the mast. Think about it -- the furling mandrel wants to be a straight line. If the mast has bend, that straight line wants to be outside the mast around the mid-point, so th emandrel and the sail around it will press against the inside of the mast and create friction.
Anyway, I asked the folk at Hunter why, when a customer ordered in-mast furling (as they admitted 80% or more did) they didn't just give them a standard straight mast with a backstay -- the furling mainsail has no roach anyway. Hunter had back channels to the magazine and I got it in the neck from the editor, so I suggested they have someone else write the review.
If your in-mast furling is to work properly, first your mast needs to be straight. If it isn't straight, and it's a B&R rig, you need a good rigger to retune it to make it straight (from what I've learned, the B&R is not easy to tune right).
Sorry about all your trials and tribulations, but many many people do like their in-mast furling systems.