After upgrading to WordPress 3.1.x, many installations suffer broken permalinks for categories and tags. This hotfix repairs the problem.
This plugin is a hotfix for permalink issues encountered with WordPress installations after upgrading to 3.1.x. It fixes the 404 error (or blank page) for menu/dropdown categories and tags. It fixes pagination for search results, categories, and tags. And, it fixes RSS feeds for categories and tags.
Before using it, be sure that your issues are not caused by plugins that modify category links, tag links, and/or canonical redirection ... by deactivating them. More details are available under Installation (above) and at Dashboard->WCS-Permalinks (after activation).