Client (Intel D845Gvsr) won't boot PXE

[dbclinton]

I've just upgraded my LTSP server to Edubuntu 12.04 everything's running 
fine...everything, that is, besides one particular client. It's an Intel 
P4 (Intel D845Gvsr) with 500MB RAM that always happily booted to 10.04.

DHCP give the client an ip address, but the screen then goes blank. 
Syslog gives me this:

Jun 25 21:23:22 dbclinton dhcpd: DHCPACK on 192.168.0.21 to 
00:0c:f1:90:74:c6 via eth1
Jun 25 21:23:22 dbclinton in.tftpd[29868]: tftp: client does not accept 
options

I figured it was a video problem so, through BIOS, I tried both the 
integrated and AGP (Radeon 9200 pro) controllers - both died after 
receiving their ip addresses.

I can't imagine it's a server config problem because the other clients 
boot perfectly.

Any ideas?

Thanks,
David