Case of the wandering Duck!!!

Heather sent me the Grumman Duck she has been using and I really like it and how it flys except that it keeps wanting to wander off to the left all the time,except on autopilot, Have tried the aileron and rudder trim but doesn't seem to help at all.Supposidly the Num5 button is suppost to center the rudder and ailerons but have seen that happen yet with any aircraft(Num lock off or on). Have enclosed the Flt. Tuning section from the cfg file, is anything needed to be changed?? [flight_tuning]cruise_lift_scalar=1.000pitch_stability=1.000roll_stability=1.000yaw_stability=1.000parasite_drag_scalar=1.000induced_drag_scalar=1.000elevator_effectiveness=1.000aileron_effectiveness=1.000rudder_effectiveness=1.000elevator_trim_effectiveness=1.000aileron_trim_effectiveness=1.000rudder_trim_effectiveness=1.000Thanks for any help. Bob Arthur (Reddog)http://www.enter.net/photoalbum/data/reddog/596406.jpgUSMC Retired