We encourage all our customers who are using Joomla 1.6 to upgrade it to the latest version.
Currently, there is Joomla 1.6.4 stable version ready to download, check updates here.
Anyone who wants to get more familiar with Joomla upgrading  process, please follow the instructions provided here.

Notice! : It is recommended to make a backup of  a website before upgrading in case any problems you will have a possibility to restore your website to the earlier version.