same for me. i replaced the battery and everything works fine except the cam. i checked all connections but the only cable that have to be disconnected are the ones for the display and the battery of course. i didn't do anything else to the device.

is it rather a hardware issue than software ? maybe i ll disconnect the battery again, suck all electricity out and try again ;-) if you know another solution please post here. don't wanna lose my N9 but without cam i wouldn't wanna use it .....