RSS feed validation time out error

Hi there,
Firstly, apart from this one issue the plugin is brilliant! The problem I have is getting the feed to validate, I get a ‘server returned time out’ error message when using the validator. I’ve checked the feed in the browser and it works, although takes ages to come up. I ran the feed link through ‘Pingdom’ tools to see if I could diagnose the problem and it said that the feed has a redirect chain which is causing the 30s+ delay on the feed being read. The redirect chain is from:
* http://www.erskinenazarene.co.uk/feed/podcast
* http://www.erskinenazarene.co.uk/feed/podcast/
Any ideas why this might be?
P.S. all my audio files are stored on archive.org not actually on the site if this makes a difference.

http://ww.wp.xz.cn/extend/plugins/sermon-manager-for-wordpress/