grub loses it's menu configuration
# - upgrading grub makes installed grub in MBR lose track of menu.lst, with
# console access can write 'configfile /grub/menu.lst' but without console
# access your machine stays in grub on boot!
not sure why it happens, is grub searching for the file from fixed location of partition, like lilo?
it could be due our packaging, as we package files to /boot/grub, not like other distros (checked fedora),
which let grub-install do the cp to /boot happen.
to repeat: just reinstall grub package on working system!