We stopped using Sysprep years ago since the Ghost Console can join the computer to a domain automatically.
If you run the configuration task at the same time as the image task, Ghost will disjoin the computer from the domain (but not delete the account in AD) before starting the imaging process.
Then when they reboot, you should see the "duplicate name exists on the network," error since they are no longer connected by domain. If you do see one error, you can ignore it for a moment. Because configuration will continue after imaging and rejoin the domain with the names you've specified for each machine in the console.
(Rt-click on a machine in console -->General tab -->edit config pararmeters. It's all in there!)
Cheers,
-Chris