Thanks for the quick reply.
I swear I did all of that before and the problem was still present. However, I confirmed the problem still existed with a particular post. I disabled all the plugins and the page appeared correctly. I re-enabled WP-Insert and YARPP and they worked correctly, only appearing where they should.
I then enabled each plugin one by one until I identified the culprit: Simple Facebook Connect.
With everything except the problematic plugin, including caching, re-enabled the site is working properly. I’ll have to work with the developer or find a different plugin for sending my posts to Facebook.
Thanks for your assistance.