Now happy Magento owners may upgrade their Magento sites to version 1.3.1.1 that was released on May 19, 2009. It is available for download here.

The Magento developers did their best to please the most exigent customers. They have fixed the bugs found earlier. So, you needn’t worry about the security any more. The new version includes some issue resolutions for Magento version 1.3.x, and an update to improve security for Magento installations using multiple domains or sub-domains in a single installation. It only affects Magento installations that have more than one domain configured as Base URL.

Other important bugfixes:

Media directive has been added to email templates filter (e.g. {{media url=”"}}).

Online customers page has been improved to prevent affecting fronted performance when this page is opened in the admin. So now your customers may browse your website without any issues.

“Invalid Request Error Message: Input parameter signature is invalid” that appears after redirecting to Amazon Simple Pay has been fixed.

Amazon payment methods titles configurable on store view scope in system configuration have been added.

Please note: do not upgrade Magento directly. Backup database and all files first. Also make sure to check file permissions before trying to upgrade through your Magento Connect Manager.