I just bought my third (!) Panasonic 25mm 1.4 lens. Having already had two, this one seems to be extremely slow in that when I take the picture at a reasonably high speed, the shutter seems to clunk very slowly and take a second or two to reset itself. My EM5 is fully updated but I can't find any updates for the lens which is at 1.0 I had to look twice to make sure I hadn't set the shutter speed to 1/15th or something. Looking at the pictures on my iMac, there doesn't seem to be any blur soooo, any ideas?