Archive.org + Tumblr + Feedburner not showing in iTunes?

[Samantha Shieh]

I'm new to podcasting, trying to see if I can upload to iTunes, but for some reason, while I have my mp3 file hosted at archive.org, I'm posting through a side tumblr blog with the first link in the post as the link to the mp3, and feedburner seems to be processing it just fine, but when I try to test it by manually going through iTunes, nothing is showing up in the feed on iTunes. 

I checked the feed through validator.org and the cover art and title are getting through to iTunes, just not the actual audio.

The tumblr is here: http://juliothepencil.tumblr.com/

The feedburner is here: http://feeds.feedburner.com/wypodcast

Any ideas?