I am having a difficult time setting up dual elevator servos to move at the same speed. Whenmoving the stick full<font size="3" face="Calibri"></font>diflection quickly both sides move at the same speed and angles. when moving the stick slowly to full diflectionone side goes faster than the other (the slaved side goes slower when full diflection is reached they are at the same angle).

My setup:
two 3010 futaba servos,
futaba 7c 2.4 tx
futaba 617 rx
using mix-1 the master is channel 2 the slave is channel 6, set to go 100% of the master

Here is what else I have tried:
switched out servos (thought one might be bad) same result
used different channels (channel 7 for the slave)
used some of the other mixes

Would it be possible to use the elevon mix?
Any advise would be very helpful. Thanks in advance
Zach