Which other plugins are active in your blog?
Is a further podcasting plugin active? (That would explain the duplicate line in the code of the RSS feed.)
A second unusual behaviour is that podPress does not seem to recognize the file type of the media file.
The most likely reason is that you have entered an Url of a file which is not of a file type podPress recognises or only a part of an URL.
What did you enter as the Location value e.g of the episode http://geekpodcast.info/nerd-word-episode-1-as-the-net-turns-2/ ?