Also, disconnect the hobbico servo and check it. I had some hitecs that didnt like servo boosters hooked into them. Also if you have extensions in the tail it might benefit you to go to the heavier guage wire!
On the subject of twisting, you need to seperate the wires(if its flat!) and then warm and twist. Typically this will keep out noise up to 36" of wire length(coupled with a higher amperage battery!)