So noone answered your questions yet , i'll give it a try without having a mac.
The Error tells it can't write to your hdd, so did you check the "w" flag? Try:Fatal: creat /boot/boot.0800: Read-only file system
to mount your hdd with writing permission.Code:mount -o rw /dev/sda
Another way would be to try out grub instead of lilo.


