[Plextalk] I can't delete a podcast that no longer exists, from my Plextalk Pocket

Hi, The subject line describes the essence of my issue. Windows Explorer (Windows Xp) can no longer see the particular podcast nor its folder: yet my Plextalk Pocket itself continues to anounce it, and when presented with the option, tries to update the episode list in the podcast feed. This it fails to accomplish, since the podcast has now also been removed from the server where it used to live. At the moment it is in my list, with other podcasts which do work. I am at a loss as to how to get rid of it. Again, Windows Explorer cannot see the podcast on the Plextalk so can't delete it, but Plextalk itself claims to see it.