ORIGINAL: haikt
i am using a selig, like they use on Avengers, it's semisimetrical, dont remember the number.
The Selig 8036 used on the Avenger is notorious for being hyper sensitive to reflex and CG location - both are critical on a flying wing as it is. If the 10% CG doesn't solve the problem, you might want to scap that wing and start again with a more stable airfoil.
D