I am using WP Super Cache on a couple of sites with great results.
However, one site I just launched is using the plugin qTranslate to provide multilingual support for the pages.
On this site, WP Super Cache seems to get confused as to what to cache, and is ending up breaking the site when Super Cache is enabled. With Half-on mode the caching works fine.
My best guesstimate is that WP Super Cache gets confused with what to cache because qTranslate is using some internal rewrite technique to determine what language to show, by prefixing all WordPress URL:s with a language code if not default.
So, to display the "home page" of our site in Swedish (which is the default language in qTranslate for us), the URL is just http://www.example.com/ - however, the English language home page is http://www.example.com/en/
So, I guess my question is - how does WP Super Cache determine what the URL of the page is?