as i recall, early on, there were numerous posts about repairs for the D700 hot shoe problem. If I remember correctly, the tolerance of the hotshoe was a bit loose allowing the flash to move enough communication with the camera was lost. some brave souls tried tapping on the top edges of the shoe with a hammer to bend them down a bit solving the problem in some cases at least.

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When no one is looking, Pigs can walk on they're hind legs