Yes, I had tried it that way already and it told me that it couldn't find a valid feed at that address. However your post made me look into something.
I tried to burn a feed for the natural-remedies category and it worked fine. So I thought maybe it was because I had made a post already in this category and I hadn't made a post in the podcast category. So I made a post in the podcast category and went back to feedburner and tried again. And whalla it now works. So I guess that's what the problem is. Apparently you have to make a post in the category before Feedburner can find the feed. ( thought I'd share this just in case someone else has this problem in the future.)
Thanks for you help.