Whether it's an original or fake SJ4000 I can not say, but I could easily make the SJCAM Firmware Update (Caution: Do not take the latest version otherwise the OK button does not work from the FW 29/10/2014 works.) Downgrade also works.
One point deduction there because the camera while shooting noise in the sound had (at least not yet tried with the old FW, with the new one.)
Update follows after the event ...
UPDATE 04/10/2015:
So, the camera noise during movies. One notices indeed only when everything around it is quiet, but there is just that. Was dissatisfied with the image quality in the dark, perhaps is also because I'm spoiled by my Nikon D800 and Sony CX730. If these "defects" can live because of the low price, but the build quality is just too bad. After a few days, the display has slowly released from the chassis. Overall, I can only give 2 stars. I've now got another favorable Action Cam bought here. Will report ...