iTunes Podcast Subscription Error: 'There was a temporary problem completing your request'

Whenever I try to subscribe to a podcast iTunes returns this message:

"There was a temporary problem completing your request. The iTunes store is temporarily unavailable. Please try again later".

It has been this way for weeks. Why? How can this be fixed to allow me to subscribe to podcasts. I have signed on to my account so I don't believe that is the issue.

[Re-Titled by Moderator]

Original Title: iTunes Podcast Subscribe