RSS Podcast Feed Error (possible hack?)

Hi guys,
I was so excited to get my podcast finally submitted to iTunes, etc and when I checked my final rss feed it has an error. (XML error: Garbage after end)

Here is the rss feed in question: http://www.francisbrothersfilms.com/feed/podcast

This is the errored line: http://feedvalidator.castfeedvalidator.com/check.cgi?url=http://castfeedvalidator.com/cache/RSS_554811d7584b5.rss

It looks like a extra line of code with a totally unrelated link that somehow found it’s way in there. I suspect a hack of some sort or malware?

I can’t believe how frustrating this is. Other then just restarting the site (I have done this with similar sites in the past and for some reason seems to keep happening), is their a better/easier way?

I deactivated every plugin and still nothing.

I am at a loss.

Any help would be great.