Since iTunes does not provide a way for other programs to access the list of podcasts you are subscribed to in your library, PowerTunes is not able to transfer your subscribed podcasts from one library to another. However, it is not difficult to transfer your podcasts manually, by following these steps:
- Open the library containing your podcasts and click on iTunes to bring it to the front.
- Select the "Podcasts" item in the list on the left hand side of the iTunes window.
- Click the File menu, then go to the Library submenu and select "Export Playlists…"
- In the sheet that is displayed, choose "OPML" from the Format pop-up menu near the bottom.
- Choose a folder (such as your Desktop) to save your exported podcasts to and click "Save". This will create a file called "Podcasts.opml" in the folder you chose.
- Go back to PowerTunes and open up the library you wish to transfer your podcasts to.
- In iTunes, select "Import" from the File menu. Find and select the "Podcasts.opml" you created previously and then click "Import".
This should make iTunes subscribe to all the same podcasts in that library as you had in your original library. Note that if you had episodes of those podcasts downloaded to the original libary, iTunes will need to redownload those episodes into the new library.