Remote Auth Problems

For the life of me I cannot get this working.

I can get iTunes on my Mac to read an RSS feed that’s stored in my S3/CloudFront secure area, and it downloads mp3 files which are also hosted in my S3/CloudFront secure area. However, iTunes on the Mac is pretty much the only application running on any platform I can get to work correctly. iOS and Android podcast apps will read the RSS feed, but won’t download any episodes.

At the moment I have no error messages to work with, but I have tried to solve my problem by trying a variety of different web hosts, but every time I get the same results.

Does anyone have the faintest idea where the problem might lie? I’m not even looking for a solution anymore, I just wan to know what might be going wrong. Every other function of s2member is working perfectly.