Not sure you guys experience this. Today I updated the K5 with the firmware to 1.11 and was playing around with the camera (with 55-300mm), then out of the blue, I can hear the mirror flopping inside for a few times. Then I half press the shutter to take some photos, and it flopped multiple times within a span of 3-5secs. Zzzz...not sure if something is wrong. Hope the mirror won't drop off due to this unusual occurrence.