m4a podcast feed problem

I’m having trouble with my podcast feed, hosted through my wordpress site. I tried putting up an m4a podcast, sent it through poderator apparently successfully, and it shows up in the feed via my site, but iTunes says it doesn’t exist. Could this be because of some miscommunication with WordPress or is that unrelated? I read about needing some different tags to get WordPress to see it as a podcast- does this matter if I’m just hosting the feed through my site but don’t care about it showing up on the front end of the site itself? The m4a file is appearing on the feed and when you click on it, a dialog box pops up to open it in iTunes (which works), I just can’t get iTunes to see it via the store/feed itself. Any suggestions? Thanks!

Here’s the RSS feed, if it helps:
http://soundonsight.org/PoderatorTeleverse.xml