grub.cfg has no menu entries for an OS; only for memtest86+

An update to a newly-installed instance of Kubuntu maverick i386 appeared to finish normally but went wrong. It has left the system with a grub.cfg with only two "menuentry" listings, both for memtest86+ (see below). Because kubuntu maverick is the only operating system on the computer, the original installation had set the timeout to zero. I am thus unable to start even a recovery console (in which I could edit /etc/default/grub).

I have two questions:
1. I believe this merits a bug report. Which package should I file a bug against?
2. I would appreciate some advice for recovering the system. I might not have framed my Google search very well.

The most readily available rescue CD is the original maverick desktop LiveCD. I have brought it up and attempted both an update-grub and grub-install, both directly from the command line and after mounting /dev/sda1 and issuing a chroot. Both efforts failed with an error message "cannot find a device for </boot/grub>|</> (is /dev mounted?)

Current state of grub.cfg:
#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  set have_grubenv=true
  load_env
fi
set default="0"
if [ "${prev_saved_entry}" ]; then
  set saved_entry="${prev_saved_entry}"
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z "${boot_once}" ]; then
    saved_entry="${chosen}"
    save_env saved_entry
  fi
}

function recordfail {
  set recordfail=1
  if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}

function load_video {
  insmod vbe
  insmod vga
}

insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 58ce6d18-460b-41b8-ad64-8c2f7dec3c2e
if loadfont /usr/share/grub/unicode.pf2 ; then
  set gfxmode=640x480
  load_video
  insmod gfxterm
fi
terminal_output gfxterm
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 58ce6d18-460b-41b8-ad64-8c2f7dec3c2e
set locale_dir=($root)/boot/grub/locale
set lang=en
insmod gettext
if [ "${recordfail}" = 1 ]; then
  set timeout=-1
else
  set timeout=10
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos1)'
 search --no-floppy --fs-uuid --set 58ce6d18-460b-41b8-ad64-8c2f7dec3c2e
 linux16 /boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos1)'
 search --no-floppy --fs-uuid --set 58ce6d18-460b-41b8-ad64-8c2f7dec3c2e
 linux16 /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
if [ "x${timeout}" != "x-1" ]; then
  if keystatus; then
    if keystatus --shift; then
      set timeout=-1
    else
      set timeout=0
    fi
  else
    if sleep --interruptible 3 ; then
      set timeout=0
    fi
  fi
fi
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f $prefix/custom.cfg ]; then
  source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###