Thank you for posting the URL of your podcast.
This RSS feed (and all the other news feeds) does not contain podcast attachments.
There are many possible reasons. One reason could be an interference with another plugin.
It looks like you are using the WP e-Commerce plugin. The current version of this plugin and podPress work by default not together.
But there is a work-a-round for this problem which will probably help at least until a new version of WP e-Commerce comes out.
Edit the podpress.php file (/wp-content/plugins/podpress) of podPress 18.104.22.168:
add_action( 'pre_get_posts', 'podPress_feed_content_filtering' );
add_action( 'pre_get_posts', 'podPress_feed_content_filtering', 7 );
(You can use the plugin editor which is included in WP. See Plugins > Edit and choose the correct plugin and file. Since there no line number displayed in this editor, you can use the search of your web browser to search for this line of code.)