Is there a fundamental difference with the D70 shutter?
The D70 uses an electronic shutter, which basically means there is no shutter. Power is turned on and off to the sensor instead of using a shutter. The actual x-sync speed of the D70 is 1/500, because this is the fastest reliable shutter speed, but you can technically use any. The D80 and D200 use traditional focal plane shutters, and anything faster than 1/250 is faster than the duration of the flash. You will see the shutter curtains cutting the image.
