1 - Are you using OS Deployment or Provisioning for this ? (I know this is in the OSD section, but a lot of ppl thing the terms are interchangeable when they're not).
2 - Are you saying that your box "just reboots" during the SYSPREP stage ? I'm not quite sure what we can try to do (or what Microsoft can do) to log activities here, but it'd be a good start if you could let us know what the OS in question is, first of all...
Generally more information on what/how you image would be good here.
LANDesk EMEA Technical Lead