The move broke stuff. First the whole site, then just the comments.
The new server has, I now learn, PHP compiled separately from Apache. Time to change the .htaccess file.
Plus, I'm now on Apache2, I learn. That has more .htaccess implications involving security settings I think I won't brag about. But I had forgotten why I did them that way, and I had to change them in a hurry.
Please let me know if anything seems more broken than usual.