Trying to take a image of a Winxp with ZCM11 SP1

I am just beginning to deploy ZCM11 agent to a few computers in a lab..we currently use ZFD7.. I installed the agent on the computer, it has been registered in ZCM console...all policies applied etc.. When I tell it to take a image of that computer, I get the following error on the workstation :
Failed to read from pre-boot server and the imaging never happens..
Not sure if it is relevant or not but the workstation is a Dell Optiplex 780

Anyone have any ideas of where to look ??

Thanks in advance
Doug