Loading Altiris Agent on a Vista machine

I have an image created for a Lenovo M57e desktop on the DS. This image has XP on it as my company has not gone to Vista yet. Out of the box the Lenovo come with Vista. I am able to add the device to the network, but when I attempt to deploy the Altiris Agent to the Vista box, I get an error on the Vista box stating the version of windows is not compatible with Altiris and the agent does not load. Without the agent I am unable to add the image to the Vista box. Any ideas on how to add the Altiris Agent to a Vista box? Thanks in advance for your help.