Both the 2108 R03 and G07 are supported. To find the supported
configurations for AIX and 3584 visit the following site:
http://www.storage.ibm.com/hardsoft/products/tape/tapesupport.htm - this
shows that they are supported with a 3584 library.

Now the confusion might lie in the fact that the 3580, 3581 and 3583 are
only supported with the 2108-R03.
This information can be found at:

http://www.storage.ibm.com/hardsoft/products/tape/ro3superserver.htm