The feed at that URL appears to be OK. It can be subscribed to manually in iTunes and works there, and the media file works OK. The server appears to support byte range requests as required by the iTunes Store.
The only errors in the feed aren't likely to cause problems: the 'length' attribute inside your 'enclosure' tag is set to '0' - it should be the file size in bytes. You have the html code (non-breaking space) in your 'itunes:summary' tags - this isn't fatal, just untidy because iTunes will display the code, not render it, so you should remove these. You have 'itunes:author' tags inside your 'item' tags where they won't do any god (and they display the email address, it should be your name). You don't have an 'itunes:author' tag in the main section so no author will show in the Store. None of this should get your podcast rejected.
Is this indeed the URL you have submitted to iTunes? - the one you originally quoted wouldn't have worked. I can't see any serious problem with this one, though archive.org may possibly cause problems (though I don't see any at the moment, the file behaves correctly) - if you can host your media file elsewhere it might be worth trying.