I'm not sure I put this in the correct category. It's
really a problem with enclosure grabbing.
The problem is that if the URL for an enclosure
referenced in a particular feed is invalid (e.g.
results in an HTTP Error 404) iPodder will save the
error page as the enclosure.
I noticed recently that I was getting .mp3 files that
appeared as HTML files instead of MP3 files on my
system (Ubuntu 4.10). That is, they have HTML icons and
context menus. I opened one in my text editor and it is
in fact the HTML of the error page.
I made a test feed with one item that referenced a file
that didn't exist in the enclosure tag. I subscribed to
the feed in iPodder and ran a scan. iPodder downloaded
the error page and saved it with the enclosure file name.