Hex is right, you should try to add the aileron slower. It is usually imparitive with this plane that you have entered a full stall. You may also want to try to add some power while adding opposite aileron, once you have entered the spin add more power and try feeding some down elevator in there to make the spin SUPER FLAT. I have flown this plane and it is easy to flat spin and will almost come to a stop when you do it right.