Hello,
We noticed that the category set in the overall podcasts is not included for each item in the podcast. This can result in a generic category being applied to the individual items. For example, publishing an iTunesU podcast of category "Business" will list the podcast itself under business but each episode will be assigned a category of "iTunesU" since it is not explicitly specified.
Two solutions would be to either repeat the podcast category for each item, which is what we've done as a temporary fix, or add a podcast category drop-down to the new media form which shows up if an item is selected in the "Add to Podcast" drop-down.