Could be the pots (problems usually show up with abnormal servo movements around neutral or the bad point, usually neutral as that is where the stick sits most of the time. ) Could also simply need recalibration. Change in centering with flipping switches (D/R) is the usual symptom when out of calibration. Unfortunaately you have to enter the service menu to recalibrate. Several aftermarket Campacs have the ability to activate the service menu and usually come with directions to do this.

Stuart