I like to use the electronic level on my X-E1. But I've noticed that if I level the camera using the bubble level on my Manfrotto 410 geared head, the electronic level on the X-E1 is off, and if I level with the electronic level, the bubble level is not centred. Another test I've tried is to level a 48" carpenter's level on a table and get the viewfinder framing guidelines to line up with the the carpenter's level. When I do that, the tripod head bubble level is centred, but again, the electronic level is not lined up. This implies that the liquid levels are matching up, so are accurate, but the electronic level is off. What do you think is going on here?