PR,
It's hard to gauge what's happening to a slope glider when the conditions are unknown. If the winds are strong, ballast might be the answer instead of nose weight. Too much nose weight could cause a loss of control response.
I agree with tall Paul on shortening up the control settings. I set mine up per instructions and have plenty of response.
The Ninja is very fast and very aerobatic. Keep the speed up, though. It's no slow flyer. Keep experimenting and you'll wind up with a really fun airplane. Hope you enjoy yours as much as I enjoy mine!
papermache