Hi!
I had installed XP and Fedora 8 and it worked.
Then I installed Ubuntu 8.04, and changed label of Fedora parition like this:
"e2label /dev/sda9 fedora" (from ubuntu)
Cause Fedora is on /dev/sda9.
I tried to fix my /boot/grub/menu.lst (the one on ubuntu root partition)
So now I cant boot into fedora. My menu.lst looks like this:
-----------------------------------------------------------------------------
# This entry automatically added by the Debian installer for an existing
# linux installation on /dev/sda9.
title Fedora (on /dev/sda9)
root (hd0,8)
kernel /boot/vmlinuz-2.6.24.5-85.fc8 ro root=LABEL=fedora rhgb quiet
initrd /boot/initrd-2.6.24.5-85.fc8.img
savedefault
boot
----------------------------------------------------------------------------------

Something is wrong in the line:
/boot/vmlinuz-2.6.24.5-85.fc8 ro root=LABEL=fedora rhgb quiet


I resolved it by back-labeling the fodera root partition to "/" form ubuntu and
changing root=LABEL=/ in menu.lst which was in ubuntu root partition.

But if someone knows how to properly rename a fedora root partition and
to modify the menu.lst in ubuntu partition please let me know.

Thanks

If you change labels, you also need to edit the /etc/fstab file. Did you do that?

no, I changed only grub's menu.lst on ubuntu parition ...