Hi Andrew,
Ghost 2003 was released in end 2002, and the last update was released in early 2004. So the device supports for the components are probably not up-to-date.
Reason for this error message is either it did not identify the volume as a boot volume, or it could not read the hard disk for some reason. Since this only happens with a one type of a machine, probably it is a device related issue. What kind of hard disks do they have? If it is SCSI disks, you may be able to get it going by using DOS drivers for the disk.
Krish