In LILO, you have to use /dev/sdb6.
But to mount the drive, you have to use /dev/hdb6.
I got the same strange thing in my notebook with SATA harddisk, and IDE layer in BIOS.
Kernel 2.4.x and kernel older than 2.6.18 report it as /dev/hda,
but kernel 2.6.19 - 2.6.21 report it as /dev/sda.
So you will have problem if you have 2 OS with those conflicting kernels.
Since I upgraded the kernel to 2.6.22, the harddisk is known as /dev/hda, consistently.