Didn't see JayB's response until after my second posting. Wow. Did you figure that out by trial and error, or is it documented somewhere?
So, to be clear, with the lock icon, the ISO/shutter are fixed at the selected values (EV compensation ignored?) - i.e. Manual. With no lock icon, the camera is in Auto mode (shutter set automatically)? What about ISO in Auto mode - is it the user set value? And then there's the EV, which I assume provides adjustment to the exposure level (shutter speed) in Auto mode. However, I do not seem to be able to change EV in either Manual or Auto Mode.