PXE boot / ltsp server now I can't boot

[Barry Williams]

I was playing with trying to setup a pxe boot server to get one of my
other computers to boot so I could install the new version of ubuntu
as the cd drive was having issue and it can't boot from usb. Anyway I
couldn't get it to work after trying tftboot and playing with
dhcp3-server and ltsp-livecd and I gave up but I never removed the
install or configs I set up. Now a few weeks later I have installed a
updated kernel and I can't boot all I get it
IP-config: eth0 hardware address <mac> mtu 1500 dhcp RARP
when I try the new kernel however the old kernel boots fine(ish the
nvidia drivers are not working).
I have tried uninstalling everything I can remember I installed and
removing the config files and reconfiguring the kernel but it still
does not work.
Any suggestions
Barry