In AJAX Cart Pro v.1.4.5 the following features are implemented:

• cross operation of “www.domain” and “domain” support. The error that can occur due to browser security violation when using both “www.domain” and “domain” is avoided.
• default, blank and modern themes support. For these themes and their modifications AJAX Cart Pro doesn’t need any additional configuration to run.
• easy custom configuration (custom.js). Now it is possible to adjust AJAX Cart Pro almost to every custom theme.

Following bugfixes are also included:

• more stable work
• out of stock products bug fix
• extension turns off  for IE6 users automatically

Get more information about AJAX Cart Pro for Magento