My HTPC has two of the subject 500GB drives. One was firmware SD15 (update needed) and the other was SD04 (update not needed). I booted the update software CD and did a scan. Both drives were visible. I selected the correct model, but when I selected flash, both drives were automatically updated to firmware SD1A. There was no intermediate drive selection or confirmation step. Fortunately, both drives updated without an issue and are running fine. There was no data loss, noticeable performance difference, or seek-noise difference after the update.
Moral of the story: If there are drives that shouldn't be updated, disconnect them before running the flashing software. It doesn't give you a second chance.
