I set my system up for a Goliath Grouper dive last Saturday using the 12-50mm lens.I figured that I would just be able to Fn-1 toggle between 12mm and 50mm and it would be OK. I ended up with a strange behavior that I haven't seen mentioned here, or I may have just missed it. The camera is set in manual, and there's an 'M' in the lower left corner of the display. There are some values for f-stop/speed. Using the up/down left/right buttons I can change the f-stop/speed. At this point I hit the toggle button and the lens moves to one end of it's travel, either 12mm or 50mm. The 'M' changes to 1 fish or 3 fish, depending on which way it went. But the f-stop and speed also change to some arbirtrary settings. Toggling again sends the lens to the other end of its travel, and changes the f-stop/speed to a different set of numbers. And at this point, the up/down left/right buttons have no control over the settings.Rolling the mode wheel off 'M' and back leaves the lens in its last position and restores the up/down left/right ability to change f-stop/speed. If I want to zoom to the other end, it's toggle, wheel, set f-stop/speed. I have fond no reference to this behavior, nor a way to set some default values for each end of the zoom. Can anybody shed any light on this behavior?