@kristapley
You’re absolutely right about the wp_head() call. I thought it was in the wrong place because the advertsising banner is in the HEAD section of your site which confuses the source view in Firefox. If you can move it, I recommend you place it in the body section as it could cause unexpected issues (I don’t think it is causing any at the moment).
Now about Audio Player:
I assume you were using version 1.2.3 before you upgraded. The Podcasting plugin includes version 2 of Audio Player. These 2 versions of Audio Player are very different and this means they can function alongside each other. However, now that you upgraded Audio Player to version 2, they are conflicting. The reason why the player cannot find the file is because Audio Player is encoding the mp3 file URL, but the Podcasting plugin hasn’t set the required option for decoding this URL. If you look at the page source, you will find two script tags with a line like this inside:
AudioPlayer.setup("https://incontention.com/wp-content/plugins/audio-player/assets/player.swf?ver=20100104124906", {width:"290",animation:"yes",encode:"yes", ... });
As you can see, the second overrides the first with no options apart from the width value.
This means that any options you set in the Audio Player options panel are ignored.
I recommend you disable URL encoding in Audio Player (Options panel > Encode mp3 URLs). This at least should fix the “File not found” problem. However, you may run into more problems in the future.
In my opinion, the Podcasting plugin should be checking whether Audio Player is already installed and use it instead of its own bundled version.
You could also downgrade to Audio Player 1.2.3 which is available here: https://www.ads-software.com/extend/plugins/audio-player/download/
Hope this makes sense.
Martin