Scirra Arcade and the AJAX plugin

I uploaded something to the Arcade, only to find that the json file I was using with the AJAX plugin didn't work. So I created this test:

http://www.scirra.com/arcade/example/17594/ajax-test

The problem seems to be that while the json file passes the file whitelist, it never ends up on the server. This link is a 404:

http://static1.scirra.net/arcade/games/17594/test.json

As a side note, txt files are not on the whitelist, and I find that a tad silly.