There's one feed in your logs that is causing some of the problem:
http://www.entrepreneur.com/podcasts/entpodcast.rssThat's actually no longer there, so PT keeps trying to update it. (I need to handle failure better I think) Unfortunately that single podcast is taking up all the 'failed' log spots, so I can't see any others having a problem. Can you delete that feed and shoot me another copy of the logs after a while?
And just to confirm, you're using 1.2 of the desktop downloader? Also, have you considered moving to OS 4.5 (not sure if that will help, but for now I'm not seeing anything that would cause the termination problem).
Let me know.
-Marcus