I called Panasonic tech support regarding the odd focus and exposure behaviors I have been seeing on my GH2. Second level tech support called back at a time when I wasn't available and I planned to call them back today. Before doing so, I decided to see if I could find a way to reliably re-create the problems. (Auto focus stops working and shutter speed locks when using a third part lens.) I was able to. The problem is me. What is happening is that I am inadvertently hitting the auto exposure lock button with my thumb. The settings in the camera for this are set at AEL/AFL and AEL-stay on. This means that whenever I accidentally do this with the Panasonic lens on, the focus locks and the exposure locks, but I don't think I noticed the second part of that as I was concerned with why the thing wouldn't focus. With a third party lens, in A mode, the focus and aperture are irrelevant and I only see the shutter speed lock. In all cases the condition stays locked until you hit the AEL button again to release it. Or, move another parameter, like AFS to MF or A to P, which is what I was doing. One of the comments about this camera in many reviews is that it is kind of small for people with large hands. I fall into that category and I agree that there isn't much space on the back of the camera to put your fingers without accidentally touching something. (I hit the ISO and white balance buttons regularly.) I also find that my thumb is short of space for having a good grip without touching something; hence the problem with hitting the AEL button. Now that I know I am doing this, the fix is easy. Just hit the AEL button and the setting clears. Alternatively, I can turn off the AEL-stay-on command, but I want to wait until I have seen this problem in the field and have noted that the AEL/AFL display icons are on, which will confirm everything, before I make the setting change. So the camera is fine. It's the operator that is at fault. But now that we know this, we can help others if they see the same behavior. Did I mention that this is a complicated camera and that it will take a while to be totally competent operating it?