To complete this thread, here's what happened: I sent the camera to Fuji. It's still under warranty, so service was free. They sent it back with this note: "I checked the RF and focus. Camera checks to factory specs. I had several people look at the film that was sent under a loupe and light box. The test shots sent are not a good way to check RF and focus." That's it. No details on what's wrong with the test shots, or what would have been a better way to check RF and focus. I'm going to try and shoot a side-by-side test with someone else's gf670.