Now CyberSEO uses the <update> XML element as the post time for Atom feeds.
Please make sure to update your copy of CyberSEO to the latest version 7.046. It fixes a serious issue with Atom feeds. You may update your copy of plugin manually via “CyberSEO->General Settings” menu, or the plugin will update itself automatically within 24 hours. The standard preset files will be automatically updated too.