if you don't see the downloadable files in mozilla, maybe its your mozilla version, or some setting?
What I do is pretty easy:
on the my feed site, choose with "step1" the lessons, with "step2" the kind of material and with "step3" give it a name. Then copy the link that stands behind the sentence "For other podcast aggregators such as Juice, copy and paste the link below".
Whenn you copy it to Mozilla, it should ask you for login and password.
In my Mozilla it looks this way, after you've done it:
i guess thats the point where you have the problem seeing anything? i had this with my last Mozilla version, but after going back and forth a little it showed up somehow. With my actual version I don't have this problem anymore and I always get the downloadable files immediately. My version is (3.6.13).
then rightclick and choose in Flashgot to download everything (or just press "ctrl+F3").
Then select your folder and the rest comes automatically.