Hi David,
Your problem could be that the answer file was being placed in an incorrect folder or the answer file is incorrect. What is your machine's OS?
On Vista platform, the default folder to hold a sysprep answer file is \windows\panther folder. If the answer file is located in another place, you need to run sysprep from command prompt and use /unattend switch to specific the answer file. You can use GhostExplorer to modify the answer file after created the image.
In general,
If you use multicasting to create sysprep's image, the sysprep part needs to be set up manually and run prior to create an image. If you use Ghost Console to create a sysprep image, After you created a sysprep configuration and load correct sysprep stuff, the Console will take care the rest in am image create task.
The Ghost implementation guide pdf file chapter 23 - "setting up sysprep" will give you some ideas on this feature.
Hope this helps,
Jenny