For anyone with a loose feeling battery door
It was really bothering me. Unlike other generations (my 8700) did the same thing but you could put a folded piece of paper under the door and it would firm it up. In this case the door has no latches on the sides so it bulges if you do that. My solution was to take two small squares of black electrical tape and put them right at the top on either side of the camera near where the back slots under the body. I put another overlapping the recess that the latch fits into...down into the recess and up and over the top edge. Its enough to tighten it perfectly. Haven't noticed it since and it doesn't make the back bulge.