Eat2Much; Have you reset/recalibrated the 4-in-1?

1) Turn gain open to the max (CW)
2) Tune the proportional till you have no unintended yaw
3) Adjust the gain back (CCW) in baby-steps until you've found the point where it doesn't jitter, but doesn't feel 'dead' either.

Take your time for it, it's worth it; creating a rock solid, whooping CX for an inlaw instead of keeping it .

Maybe that helps...