WordPress Custom Post Type Pagination

I’m aware there are many posts on this topic on the forums — I’ve done a search. After an hour beating my head against this problem, I’m stumped. I am trying to run a custom post type query and enable pagination on it. I can’t do anything to get the pagination to work. To clarify: I’ve followed all the prescribed solutions, but the posts don’t advance when I click the Previous button. The same page loads, with the same posts displayed.

Pastebin: http://pastebin.com/Ke9Hg1zC

The only conflict I can think of is that the post-type name ‘podcast’ and the page slug ‘podcast’ are identical, which I saw could cause issues. But those folks were getting 404s, which I am not, so it doesn’t seem to be a permalinks issue, but an issue with my code.

Any ideas?