According to my webhost, everyone on my server has been moved to a new box. They’re still not sure why the old one was failing, but so far everything looks good on the new one. Thus, I can post normally again, and comments should be working as before.
By the way, the change occurred yesterday around 1:30 PM Central time, so if you tried to get here around then you would have been unsuccessful.
Anyway, things should be back to normal here. Thanks for your patience.