Root Mount Problem

[Rossen Naydenov <rnaydenov@creditreform.bg>]

I have upgraded my box to kernel 2.2.18 and I'm using lilo from unstable
this is how my lilo.conf looks like:
boot=/dev/hda7
root=/dev/hda7
install=/boot/boot-menu.b
delay=20
map=/boot/system.map
append="mem=128Mb"
vga=extended
read-only
image=/boot/vmlinuz-2.2.18
    label=last
image=/boot/vmlinuz-2.2.17
    label=old
other=/dev/hda1
    label="Windows NT"
    table=/dev/hda
But when it starts it says :
unable to mount root fs ob 30:7b
cannot open root device at 30:7b

But if on the boot prompt I say root=/dev/hda7 everything is OK
Any ideas?
Ross