I've owned a Fuji GA645i for close to five months now and it's worked flawlessly, but lately it seems to be underexposing the top 1/6th of the frame by 1-2 stops. I'm baffled, bummed, and at a loss as to what it could be. I thought perhaps the rubber hood I've been using had become bent, but that doesn't appear to be the issue. No aperture blades appear to be sticking and I'm completely out of ideas. The camera only has 1700 actuations and I can't imagine it being the shutter at that low of a count.

Has anyone run into this before with the Fuji GA series or other cameras?