So I’ve got a great half-explanation on my hands that goes nowhere to actually solve my problem. What I guess I need to do is figure out what code my post-new.php page is looking for, ascertain whether the code is in fact where it’s supposed to be, and either find and replace it or not, and fix it if so.
This may be a perfectly simple exercise, but from here it feels daunting.
UPDATE: I’ve gone through and systematically re-uploaded all of the standard WordPress files except for those in the root directory, so that would seem to narrow things down. I’ve now just got 22 possible culprits to weed through.
UPDATE 2: Okay, I dunno. I’ve gone through and visually compared all of the remaining files, and combed through the unique files for code that doesn’t belong, and I’m turning up nothing. So I’ve no clue why I still have this problem with POST.PHP (and, to a lesser extent, with POST-NEW.PHP).
Update 3: It’s not a browser issue, either. I knew it wasn’t, because the pages used to work just fine in Chrome. I hit the same problems in Opera as well, so there’s something on the server side that just isn’t working.