Problem:

• the /boot was not mounted during the upgrade
• for some reason, we can't mount the /boot after the upgrade (edit: it was because of evms)

Ideas:

• boot using a LiveCD to be able to enter the broken system

    mount /dev/sda5 /mnt
    for dir in proc sys dev ; do mount --bind /$dir /mnt/$dir ; done
    chroot /mnt
    mount -a

• move all new installed files from the bad /boot (sda5) location to the real /boot (sda1)

    umount /boot # just in case it would have been mounted with mount -a
    mount /dev/sda1 /mnt
    mv /boot/* /mnt/
    umount /mnt

• remount the real /boot at the right place

    mount /dev/sda1 /boot

• run update-grub and then re-run the grub install on /dev/sda

    update-grub
    grub-install /dev/sda

• come back to the LiveCD and umount everything

    umount -a
    exit

    for dir in proc sys dev ; do umount /mnt/$dir ; done
    umount /mnt

• add this to the beginning of /etc/acpi/hibernate.sh

for PID in `/usr/bin/pgrep xfdesktop`; do
  DBUS_SESSION_BUS_ADDRESS=`(/bin/cat /proc/$PID/environ; /bin/echo)|/usr/bin/tr "\000" "\n"|/bin/grep DBUS_SESSION_BUS_ADDRESS|/bin/sed -e 's/DBUS_SESSION_BUS_ADDRESS=//'`
  LOGIN=`/bin/ps -ouser -p $PID --no-headers`
  DBUS_SESSION_BUS_ADDRESS=$DBUS_SESSION_BUS_ADDRESS /bin/su $LOGIN /usr/bin/xflock4
done

http://ubuntuforums.org/showthread.php?t=493697