I too have the same issue but with a 8100. The phone worked fine and I turned it off. When I restarted it, I get the Genuine Battery issue. I have 3 of these batteries and all 3 work fine in my 8300, so I know it's not the battery. I also know that the phone has never been wet(proven by the wet indicators on the phone and battery). Guess no -one else has had this issue yet since there haven't been any responses.