So I’ve discovered the root cause of my site problems over the last few days.
As I host the site on my home PC, my IP address changes from time to time. I therefore use IP updating software from my domain registrar, DNSExit. That software worked just fine, and updated the domain IP just as it was configured to do. Unfortunately, a Russian spy sneaked in and mis-configured said software.
Based on my previous post, see if you can figure out what’s wrong with this configuration:
Screenshot of DNS Update configuration
As noted elsewhere, I did my best to fight off the spy, but the damage was already done, and in sneaky, nefarious fashion.
Either that, or I’m an idiot. I like the bit about the Russian spy, myself.
Loonmagnet 
Perhaps *you* are a Russian spy! That would explain it all.
That would explain certain things, but would raise a whole host of other, more disturbing questions.
At this point, I think Occam’s Razor is strongly hinting at the latter hypothesis.