Mine also seems to have a tendency to tip stall at slower speeds - especially on landing. Mine's a bit heavier - around 14lbs with a ZDZ 40.... figured the extra weight wasn't helping the tip-stall situation, but wow does it ever have vertical performance!

Anyway, I did a little experimenting that seems to be working out very well. What I did on mine was program in a 'landing mode' - actually used the "airbrake" program mix on my Futaba 9C. In this mode I've set both ailerons to go 'up' about 3/16", and the elevator to go 'down' just a tiny bit to offset the slight pitch-up tendency of raising both ailerons. Anyway, the theory is that this will effectively washout the wings..... seems to work. Lands just great now with no tip-stall! Still flying the rest of the flight in 'normal' mode, could try leaving the 'landing mode' on all of the time, I suppose.

Still continuing the experimentation, but so far so good.

BJH