Sysprep with Windows 7 will not correctly rename and join computers to the domain. It does the join to domain before the rename. Means you get computers in the domain named WIN02349XXDF0S, when the computer is really named BOB.
Install the FOG Client ([url]http://[yourfogserver]/fog/client[/url]) on your image and let fog rename and join the computer to the domain. You’ll need to get FOGCrypt onto a windows machine to encrypt the password you use to authenticate to the domain, but there is info in the wiki on how to do that.