I have several blogs on the same VPS server (all WP 3.0.4 and Supercache 0.9.9.8)
As of a couple of days ago, I noticed the following error in the error_log (of all blogs):
PHP Notice: Undefined variable: php_fd in /wp-content/plugins/wp-super-cache/wp-cache-phase2.php on line 572
Anything serious? Can I do anything to avoid it?