404 error when submitting Podcast RSS feed to Itunes

My blog is http://www.thisweekinforex.com/blog
I cannot seem to submit my feed to Itunes for Podcasting.
The podcast feed generated in my WordPress Blog by Podpress & Powerepress :is:
http://thisweekinforex.com/blog/?feed=podcast .
Note; This feed does not validate.
I am getting error that reads: We had difficulty reading this feed.. Bad http result code 404.
I have tried re-installing the plug-ins. but the same feed is generated.
Itunes tell me that WordPress have to resolve this one.

Can you please help?
Thank you