Hi Ed,
I checked my MAN Arrow plans and the CG is almost exactly 1" in front of the main gear per bjr above. I would check the servo resolution and centering. Do you have a servo test function on your transmitter (I know Futaba has it, or at least the higher end radios)? It will cycle your servos slowly from end point to end point and you can check for anomalies like dead spots, twitches, etc. If the servo centers accurately on the workbench then try checking it with the engine running. Check all the connection points of the aileron linkages for slop. If it is set up for one aileron servo driving the ailerons through torque rods, check the clevis pins and the torque rod holes.
Keep us posted and good luck!