When stringing with a Prince Neos 1000 I noticed that the racquet doesnt seem to clamp down very tightly and when pulling tension the racquet semd to slide around a little. Is there a way to keep the racquet from doing this on a 2 point system. Also, I noticd that when stringing on a Neos there was a slight distortion with a Head ti.s6 racquet. Are there any aftermarket 6 point or 4 point mounting systems for this stringer. Any help will be greatly appreciated.