futtta on "[Plugin: Autoptimize] Headers"

the versions pre-1.6.0 had an max-age that was too long. the current code does this (cfr. http://plugins.svn.wordpress.org/autoptimize/trunk/config/delayed.php);

$expireTime=60*60*24*355; // 1y max according to RFC
header('Cache-Control: max-age='.$expireTime.', public, must-revalidate');
header('Expires: '.gmdate('D, d M Y H:i:s', time() + $expireTime).' GMT');
header('Last-Modified: '.gmdate('D, d M Y H:i:s', $modTime).' GMT');

hope this helps,
frank