Anybody else experience really bed servo spasms on their elevators?

HD "y" (no amp) w/ ferrite ring right out of JR 945 RX , about 5' of hd gold extension on each leg of "Y" to both 8611 servos.

I've replaced all wiring with no sucess- if only 1 servo is plugged in it doesn't happen.

Will happen on a 4 cell pack, but really gets bad on 5 cell .

Horizons site says new MOTORS and case tops have been put in the 8611"A"

It happens with nothing else plugged in RX, even with TX turned off (failsafe/hold)

I suspect "crosstalk/feedback" or bad feedback pots between the ele servos- the Horizon tech I spoke to says he hasn't heard of a problem like this.- but he does say not to run greater than 2' extension without amplification-(I know alot of our planes have more than 2' of extensions!)

I'm just not to thrilled about R+R the servos ,shipping and possibly being told "theres nothing wrong with them"

Jake