Pages pulling in posts after custom permalink change.

Okay, I think I might have messed up. For a site, I wanted the permalinks to be sitename.com/category, because, well, it looks nice. I made my post permalink "/%category%/%postname%/" and set my category slug to "." That did the trick, but I realized that it was bad overall for my site.

The problem is that, when I switched back to "/%year%/%postname%/" and "topic" for post and category permalinks respectively, if I publish a page now — say I create an "About" page — there is a loop of my latest posts below the page.

Any ideas what might be causing this and how I might be able to fix it?