When I landed at the end of a flight today, the camera was making the "Da..............Da..Da.." noise. when I power cycled the craft everything was normal again. There is a firmware file on the card. (WM610_FW_V01.02.01.06) and the firmware update result file shows having been modified today at the time of the flight the last three entries are interesting : ========== 2015.08.13 09:45:15 ===================== Packet: WM610_FW_V01.02.01.06.bin Result: Abort. The firmware on the SD card is identical to or older than the current firmware on the aircraft. ========== 2015.08.16 09:25:21 ===================== Packet: WM610_FW_V01.02.01.06.bin Upgrading ... Result: Success. ========== 2015.08.16 09:35:51 ===================== Packet: WM610_FW_V01.02.01.06.bin Result: Abort. The firmware on the SD card is identical to or older than the current firmware on the aircraft. As far as I know, all batteries had been updated back when I ran the update a couple of weeks ago. I did briefly get a battery error message when prepping for takeoff, but it was on the screen for only one flash then left and the battery checked out fine on the details page. Does anyone know why the firmware suddenly decided to update? And, worryingly, I was able to start motors without any noticeable delay, possible just two mins from powerup to takeoff.