I have also experienced servo glitching using Hitec digitals with a Futaba reciever in my 1/4 scale Extra.

I have not flown my Extra in quite some time due to this problem. I am getting ready to buy the electronics for a Comp-Arf 2.3 and I am having a difficult time that Hitec digitals are the way to go because of this problem.

I have considered using JR8611's but the servos have a reputation of developing slop, Futaba does not seem to have the power and torque in their servos that I would like. (the physical size of the servos is an issue for all control surfaces except rudder.

Hitec has the servos I need and would like but then there is that servo glithing issue!!!

Keep posting your information as I am very interested in any information that could shed light on this problem.