Hmm… Programmer’s error, I forgot to update the variable name in the procedure call when I updated it in the earlier code.
I may still try the mailing list in the future. If I simply have newbie questions over protocols, such as ATOM, should I message the wp-xmlrpc list or the wp-hackers list? It looks like the xmlrpc list is more for WordPress developers and hardcore blogging applications developers to communicate. (Here’s hoping you come back to view this message.)