Johnny, another thing to do: assign channel five to a stick (such as aileron) so that you can vary the movement (besides just one end to another like a retract switch). Then you can see that the servo is not driving hard against the stops. Take note of the servo arm position when centered, all one way, and then all the other way. Then go back to your current configuration. Is it now very far from where it was when it was assigned to the aileron stick at center? One end? The other end?

I have one of those FMA Servo Labs that Rob was talking about. It really is a great tool.