We just got in a few new Dell Optiplex 620 workstations. We set up PXE
boot for imaging. The PXE boot process works fine, can ping everything we
need.

When we type IMG to start an imaging process the blue image screen pops up
then shutsdown. You can't even initiate an image via command line. Again
the blue image screen pops up and disappears to the bash prompt.

Any clues as to why this happens?