This is a previously installed and working WP 2.5 site, now with Super Cache 0.6.6. The configuration is all defaults. I have used this plugin before and it installed and just "worked". But on this installation there is no caching at all. The WP-Super-cache was "enabled", the ROOT htaccess was updated, the wp-content/cache directories were created (but no cache files are being created), wp-cache-config.php is writable, there are no errors in the Apache error_log, no evidence of comments being embedded in the HTML source, and no errors showing in the Admin. No nothing.
Thanks for any help on where to start looking!
This is after about an hour of traffic:
$ find wp-content/cache -ls 8110416 4 drwxr-xr-x 3 apache apache 4096 Aug 4 10:45 wp-content/cache 8110514 4 -rw-r--r-- 1 apache apache 81 Aug 4 10:45 wp-content/cache/.htaccess 8110513 4 drwxr-xr-x 2 apache apache 4096 Aug 4 10:42 wp-content/cache/meta