The official Magento blog has announced the availability of the Magento CE Version 1.4.0.1.

You are free to download it but you’d better backup your database before you upgrade to the latest version of Magento. In case you plan to upgrade through a Magento Connect Manager, don’t forget to check file permissions.

Note: the Magento Team suggests disabling Magento cache before upgrading.

As usual, new features as well as fixed issues are provided at the release notes page. Diff files are also available for download.

If you have any problem or you find any bug, please report it in the bug tracker.

At the end of this article we’d like to share a few important notes that are published on the official Magento blog.

“Important Note 1: If the Magento Compilation Module is enabled it must be disabled before attempting to upgrade. After upgrading is done, click on “Run Compilation Process” to process and enable it again.

Important Note 2: If you are running Magento in a cluster environment and are using a shared cache (e.g. Memcached) you will now need to also make sure to configure Magento to use Database as the “slow” backend cache.”