well i tried it on chrome and nw, and in both happens the fps stays in 60 but i looks jerky.
i tried firefox, but firefox does not give me 60 fps, so i cant test it there, becuase it runs horrible.
phenom x4 965t black edition
8gb of ram
radeon hd 6950 xfx 2gb
i dont know whats causing it, but the previous version of NW was running fine for me.