32XAA faster smoother than 16x as per Furmark GTX 480

Guys can anyone explain why 16 MS AA has worse FPS and benchmark result than 32X with latest furmark and latest nvidia 260 driver on my new gtx 480 at stock speeds?I cant explain it, regardless of resolution, full screen or windowed all the same results, my frames are much less in 16x than 32x and my score is low temps are the same. We aren't talking a few frames 16xaa in furmark shows an average of 24 and i get 53 with 32x. Why would the 32 run much smoother and give better results than 16x? ALso in a game 16 is slightly faster and 8 is even faster and none (AA) super fast. In games it makes sense.