Custom Sysprep config file not processing

What am I doing wrong? I have created and deployed images on several managed computers in my organization but having trouble imaging unknown computers. I know that I need to add the new machines as predefined and I can get the computers to take an image. But after I boot to production, the computer will sit until I logon and click on the Sysprep dialog box. (See attached) I am using a custom sysprep file when deploying my image. But why isn't this getting processed until I log on to the machine and manually click this popup?

Thanks,

~Michael