OK here is my idea

i think my servo wires are the problem. i have removed the 2 elevator servo's causing the problem and replaced it with 2 different servo's and also geniune JR Extensions. if these are connected to either receiver the plane glitches. if i however remove the 2 servo's the glitching stops and there is no problem.

if this is my problem how do i overcome this as the extension are just long enough to reach the receivers? and yes the original servo extensions i had in were curled heavy duty servo extension.

Michael