Seems to be working fine now. :-/
210 and 211 errors mean that the file containing the list of topics on a particular board can't be opened for read/write access. (They're triggered in different portions of the Post.pl script.) But I honestly don't know why they would have come up because the file for Current Talk was available on the server. If it hadn't been, the list of topics wouldn't have shown up on that board.
Odd...
But then, computers often have minds of their own.
Chalk it up to some sort of temporary server glitch.