I extracted the boot image of the latest moose updater and did a file compare with the previous version using a hex editor. There are numerous differences. Whether these changes are additional validity checks, bug fixes to the flashing software, or actual changes to the SD1A firmware, I wasn't able to tell. I posted a question on the Seagate board as to whether my 500GB drives should be reflashed with this latest updater, but there were no useful replies. Edit: I reflashed both of my 500GB drives today with the latest SD1A flasher. The update was uneventful. Both drives are operating okay. One drive was originally an SD15 and the other was an SD04 before the first flash to SD1A. They operated okay after the first flash also.