Anti aliased borders after deleting area in photoshop

Thanks for the tip, XTOTHEL. It's a lot less clunky than I first thought, but I tend to work mostly with the pen tool so I'd still like to find out what's causing my selected areas to become anti aliased upon deletion.

Devil, could you show me where the checkbox is? I'm not sure which one you're referring to, and I'm not sure if I've already unchecked it. ):