There is a new D200 firmware update (2.0) available from Nikon USA. The firmware addresses only minor issues, apparently nothing very important to UW shooters, but Nikon is known to "hide" improvements in their firmware upgrades. Here is the text from Nikon:
Issues addressed with firmware version 2.0.0
1. Image authentication item has been added to the setup menu. The optional Image Authentication software is required to authenticate images.
2. A Wireless transmitter item has been added to the setup menu. This item is available only when the optional Wireless Transmitter WT-3 is connected to the camera.
