Jeff,
I'd send this thread into Swaro with your bad units and ask for replacements. It seems like you've been unlucky enough to have uncovered an electrical/electronic flaw in at least some of their range finders. I'm sure they'd like to get to the bottom of it also. Somebody on the production line is getting a bad solder joint or some other such problem that's generating your grief.
Plus, once they see their product getting some problematic press via your effort to get to the bottom of the issue, I'm pretty sure they'd be interested in a happy ending to your thread.
Just delete this post from your thread. Or if you want, send me a PM and I can delete it so it doesn't look like we've collaborated operate the Swaro LRF units.