Hmmm, it seems that a part of the popularity contest plugin has broken too much for my limited coding capabilities to fix. I tried modifying a few entries but it did not work very well. Oh well, I’ll just wait until the newer version. Until then, just don’t expect to see the most popular posts by category
I just hope that the version of the plugin I am using will be updated accordingly or at least that the original author will take this opportunity to implement the changes Richard made so that it can work with WP-Cache from now on.