Huh. Well that's wacky -- now it's working. Almost.
When I wrote my post here I was having problems with the most recent post, the one titled "Echo 32." Now there's a new one up after that, and you guys are right, everything's working fine on the new one. Also on the first one. But on Echo 32 I'm still having those problems. So it looks like the problem is with that one individual post. That's weird...