I am using PodTrac so I can upload my episodes to iTunes Podcast and when i put my RSS Feed URL it is giving me an error. I contacted them and asked what was wrong and they said
"We cannot see your feed since it loops back upon itself in a complete circle. Do you have a source feed that you are redirecting to another feed? When we ran this through a redirect checker, it looks as if the URL redirects to itself – which is likely causing the redirect loop.
I think this may be a Support ticket item for SoundCloud since you have a SoundCloud feed. The SoundCloud folks are very helpful and they will have a solution for you."