If system has A Mylex DAC960 controller and regular SCSI controller with disks attached to it installer thinks that /dev/sda is bios drive 0x80. But LILO thinks that /dev/c0d0 is BIOS disk 0x80, which is correct in most cases. This bug makes the system unable to boot. Problem can be solved by booting with bootdisk and changing lilo.conf boot= line. Currently installer offers only two possible locations to place LILO: bootsector of root partition and beginning of the disk, which installer thinks to be BIOS disk 0x80. Maybe installer should offer other places where LILO could be installed. These could be beginnings (MBR) of all available disks of system.
I have forwarded this to a devleoper for future consideration in the installer.