1/200th is the best I could do. Unfortunately that leaves me with some ghosting on action pictures. I wonder if the different models have different shutter speed capabilities with flash where I can use a faster shutter speed.
To eliminate the ghosting, use Manual exposure mode and Manual ISO. Set the shutter speed to 1/200th sec. and the aperture and ISO to under expose for the ambient light by three or more stops. With the SB-900 in TTL mode you will be able to use the short flash duration of the flash to freeze the motion of your subject.
Also make sure you are in TTL mode not TTL BL mode.
Marty, I finally got a chance to try your approach and it really worked. I actually could only stop down one stop on Manual. I've attached two photos, the first is using Auto-900 on TTL mode, the better one is using the camera on Manual, 1/200th of a second at F5-6.
Since both images appear to be shot from the same location and about 2.5 minutes apart the ambient light should be the same.
There is actually about a 3-stop difference in the ambient exposure.
Image #1 : 1/60th sec. , f/4.5 @ ISO 1400 Image #2 : 1/200th sec., f/5.6 @ ISO 800
Shutter Speed - 1 2/3rd stops Aperture - 2/3rd stop ISO - just under 2/3rd stop
Image #2 is underexposed by just under 3 full stops compared to image #1 for the ambient light. Since Image #1 was slightly underexposed for ambient already, image #2 was underexposed by more than 3 stops.