Retrospect needs to be updated with the latest versions of the application and the driver update in order to work with most AIT drives. We recommend downloading and installing the latest versions which can be found here.
If you're using Mac OS 10.5 you can use Time Machine, which is built into the operating system. If you don't have Mac OS 10.5, there are shareware and inexpensive programs available to automate the process of backup and restore. Here's a few good ones to try: http://www.shirt-pocket.com/SuperDup ...