Can't find downloaded audio from our iTunes U Site

We are testing a password-protected site.
We want students to be able to directly download content to their iPod Touches, without going through a computer. Once downloaded, we can see video files, but not audio ones. This is on iPod Touch 3G, freshly restored with iOS4. Can someone else test this for me?
Go to http://ilex.conncoll.edu (rough visual prototype pages)
Enter demo for user and demo for pw. You will see thee podcasts.
Guitar Recitals has only one group. I downloaded 1-Italiana and 2-Etude in Bm. Once downloaded, I can't find them anywhere on the iPod. However, if you do a search, they come up and can be played!
Videos are not a problem, they show up under Videos.
Anyone have any idea where the audio files would be listed?
Are we doing anything wrong with adding metadata? Right now there is only an image.
The audio files show up correctly in iTunes on a computer, under iTunes U as part of a podcast, the problem seems to be the iPod. This is also an iPod support question, but I thought I'd start here.