Unregistered workstations not getting default base image.

NW6.5sp5
GW7.01

I have set up a imaging server policy to force down a base image to unregistered workstations.

But it does not work!

It's starts up, loads the PXE menu, I select Imaging...

It boots to Linux and then quits with

"Error: Image object did not contain image file information"

I have tried re-creating pretty much everything without any further success??

HELP

Rob