A /boot partition is necessary if your BIOS is old and does nont support booting from beyond the 1024th cylinder. I use a /boot partition on an old HP 166 netserver for example. IIRC there was a bug w/ lilo and perhapsyou just need to reinstall it. Use a boot floppy to boot Linux or use the Knoppix cd, mount your /root partition, chroot to the mount point for your /root partition and rerun lilo.