iTunes is freezing when I open the Podcasts tab.

This morning I left iTunes running so it would download new episodes of the podcasts I subscribe to. When I returned to my computer, I found that iTunes had automatically deleted my entire podcast library without my permission, and had automatically started downloading every episode of every show I subscribed to. I was obviously perplexed by this, so I cancelled the excessive downloads and tried just to download the new episodes. However, iTunes promptly froze. Now every time I go to the Podcasts tab, the program freezes and I'm forced to close it through the Task Manager. Anyone know why this is happening or, more importantly, how to fix it?