Problem with grub & new kernel

[sasa]

Hi, on Fedora Core 1 with kernel version 2.4.22-1.2115.nptl. after that I 
have applied a kernel patch and rebuild the new kernel, I have modified 
grub.conf but when I try to make the boot with the new kernel version I 
have:

VFS: Cannot open root device "sda2" or 08:02
Please append a correct "root=" boot option
Kernel panic: VFS: unable to mount root fs on 08:02

..my grub.conf is:

title Fedora Core ()
root (hd0,0)
kernel /vmlinuz-2.4.22-1.2115.nptlcustom ro root=/dev/sda2 hdc=ide-scsi rhgb
initrd /initrd-2.4.22-1.2115.nptlcustom.img
title Fedora Core (2.4.22-1.2115.nptl)
root (hd0,0)
kernel /vmlinuz-2.4.22-1.2115.nptl ro root=LABEL=/ hdc=ide-scsi rhgb
initrd /initrd-2.4.22-1.2115.nptl.img

..when / correspond sda2.
Thanks.

------
Salvatore.