My feed 404'ed?

404 is the standard error message for 'File not found' the URL you quote is Mevio's page people are sent to when a request is made for a non-existent file.

iTunes now has that page registered for your podcast feed, and so of course subscribing does not work and the Store page cannot update. A change to the feed URL is made by including the 'itunes:new-feed-url' tag in the feed - this is not present in your feed and I assume you didn't do this.

Another method is the use of a '301' redirect on the server. You need to ask Mevio whether anything of this sort has happened.

However, in order to get the feed correct in iTunes you would need to be able to place a feed, complete with the redirect tag, at that URL, which plainly you aren't going to be able to do.

This means you are rather stuck, and have only two options. The first is to abandon the old feed altogether. You should get the old podcast removed from the Store - instructions here - and submit your new feed as an entirely new podcast. You will probably need to make a small change in the title, as a bug in the Store software may tell you that the podcast has already been submitted: and of course you will lose any subscribers or comments.

The other option is somewhat uncertain. iTunes Support is notoriously unhelpful, often sending back form answers which often don't deal with the actual problem, or referring the questioner to the Discussions Forum (which may have sent the questioner there in the first place): however it has been known for someone to persuade Support to shift their podcast to a new URL, so it's worth trying. It's probably just a matter of luck who you get. To contact iTunes Support, go to http://www.apple.com/support/itunes/ - click on 'Other iTunes Store Features' in the list and then on 'Podcasts'.