Sem-Cache already delivered great results in website performance when compared to WP Super Cache and W3 Total Cache. With version 2.11 of Sem-Cache, performance is improved and a few hidden bugs squashed. Simply upgrade the plugin. I would recommend turning caching off then back on to get the cached rebuilt immediately.
Version 2.4 of the Semiologic Cache Plugin for WordPress has been released. WordPress sites running the Semiologic Cache plugin experience vastly improved site performance and this release improves upon that.
This version features enhanced Apache htaccess rules for better performance and overall user and browser experience. Additionally, the correct canonical url is now enforced when caching is enabled if the incorrect www or non-www version of the site’s url is used to visit the site.