What is hda? I haven't dual booted with multiple drives, but I think it may be a problem with being on IDE secondary position. Is BIOS set up to boot from the slave drive first? Another option to try is switching the linux drive to IDE primary and whatever hda is to IDE slave. LILO can then handle booting everything. Also, if you change lilo.conf, make sure to run the command "lilo" afterwards. Otherwise your changes won't be registered.