Rick,
There are a few things to cover here.
1. We know of a problem with 4.2 where some units do not turn on if power isn't near or above 12.5V. This is only true for units without a battery, so if you have a good battery we don't expect this problem. That is why we wanted to take a look at the battery. Because even if you upgrade to v5.0 and get this resolved we want to make sure your battery is good.
2. There could be a totally unrelated temperature issue at cold temperatures. But it isn't clear which at this point. v5.0 may be a good way to rule out half of the possibilities.
3. The product rebooting during crank can happen depending on how low the voltage gets. This does indeed become moot if you have an internal battery because that provides a "switch-over" during crank. So once we get you battery back in there, I suspect that it won't be an issue. In general, the unit will reboot if the voltage goes much below 10V for too long. Not a real issue, just annoying for you, so the battery should do the trick there. And just so you know, EMS products behave a little differently than EFIS products because of circuit differences, so the behaviors will not exactly align.
So get your battery back in there and v5.0 and then see where things are. I suspect most of these issues will be resolved, except, I am a little concerned about the temperature part, so again, let's rule out some things and go from there.
Let us know, we'll make sure you get this resolved.