David Poch
EF1
That's a critical feature for me as I'm going to be using the camera as a dashcam, and want set the focus and forget about it.
If I remember right my SR-5 stays in infinity even if it auto shuts down, I do think that you have to set it back if you power it off. I never ran into it resetting on me when using it since I have it powered up with the inverter. I don't see why the SR-12 would be any different.
Oh yea one more tip... turn off the demo mode in the menu if you leave it powered on for a long time.