I've regrettably had to deactivate WP Super Cache for the time being.
The page caches are regenerated with each hit, as has been noted on previous threads, but of more concern is that when WP Super Cache is activated, the website's pages when viewed tend to revert to a previous version of the design (but not to previous content). This happens even when the cache has been manually deleted several days ago. When I deactivate or elect not to cache, all is fine.
WordPress 2.8.4 and latest release of WP Super Cache. I use very few other plugins.