Error message when navigating to the Theme Optimiser

Error message when navigating to the Theme Optimiser:'a:5:{i:0;s:62:"Mage registry key "_resource_singleton/tag/tag" already exists";i:1;s:5457:"#0 /app/Mage.php(222): Mage::throwException('Mage registry k...')'

Please update to the latest version of Fooman Speedster Advanced.