RSS= Really Shitty Sycnronization?

Ok, I thought this shit was easy, but hear my tale. A tale of three RSS readers: Itunes, Bloglines, and NewsFire. The feed in question: GeekBrief’s HD podcast feed.

Taking the URL (http://www.podshow.com/feeds/hd.xml) and pasting it into the various RSS readers yielded two results:

Bloglines: Saw all the available episodes and let me download them.
Itunes: Got nothing.
NewsFire: Got nothing.

How is this possible? I can see if the feed itself is just messed up, by why is Bloglines the only one that can see this?