I'd just leave the existing podcasts that are using category podcasting as they are for now. I'm mostly trying to get a mental image of what's happening on your site.
From your WordPress dashboard, hover your mouse over Posts and click Categories. There should be a category there for Booze and Phasers under the Shows category with the slug booze-phasers. Try editing the slug to something like booze-phasers-podcast and save the changes. I think maybe the issue we're hitting here is that one of your podcast channels has the same slug as the WordPress category and that's why the link is going to the podcast feed instead of the category archive page.
