nbgrub fails to boot HD

[Egan Ford]

I am attempting to use nbgrub as a cluster remote boot control manager
(we currently use pxelinux and eb).

This is the tftp downloaded config file we use for installation:

default 0
timeout 5

title install
root (nd)
kernel /tftpboot/xcat/ks72z root=sd0s1 mem=128M console=tty1
console=ttyS1,9600 ks=nfs:jupiter:/install/ks72/computensl72-compute.ks
ksdevice=eth0
module /tftpboot/xcat/ks72.gz

This works perfect, after a successful installation we change the tftp
downloaded config file to:

default 0
timeout 5

title hd
rootnoverify (hd0,0)
makeactive
chainloader +1

Per the documentation to chainboot the native boot loader (lilo in this
case).

But we receive the following error:

Error 13: Invalid or unsupported executable format.