In order to get a clearer picture of your setup, how about booting your Ubuntu Live CD, download the Boot Info Script to the Live CD desktop:
https://sourceforge.net/projects/bootinfoscript/
Then do:
sudo bash ~/Desktop/boot_info_script*.sh
That will create a "RESULTS.txt" file in the same directory from where the script is run, namely your desktop; please copy/paste the contents of the RESULTS.txt file to your next post, highlight the copied text, and click the pound/hash sign "#" graphic button in the Ubuntu forum message box so that the text will get "code" tags put around it. The results of that script will help clarify your setup and hopefully what the solution to your booting problem might be.
I have also gotten the Grub Error 15: File not found error and have the result log for you to see.
http://pastebin.com/f72795fc1
Also, if you could, I would like it if you could post the solution onto my thread so that when other people see it they can also find it out.
/yes
============================= Boot Info Summary: ==============================
=> No known boot loader is installed in the MBR of /dev/sda
sda1: __________________________________________________ _______________________
File system: ext3
Boot sector type: -
Boot sector info:
Operating System: Ubuntu 8.10
Boot files/dirs: /boot/grub/menu.lst /etc/fstab
sda2: __________________________________________________ _______________________
File system: Extended Partition
Boot sector type: Grub
Boot sector info: Grub0.97 is installed in the boot sector of sda2 and
looks at sector 34107775 of the same hard drive for
the stage2 file. A stage2 file is at this location on
/dev/sda. Stage2 looks on partition #6 for
/boot/grub/menu.lst.
sda5: __________________________________________________ _______________________
File system: swap
Boot sector type: -
Boot sector info:
sda6: __________________________________________________ _______________________
File system: ext3
Boot sector type: -
Boot sector info:
Operating System: Welcome to openSUSE 11.1 -
Kernel ().
Boot files/dirs: /boot/grub/menu.lst /etc/fstab
sda7: __________________________________________________ _______________________
File system: ext3
Boot sector type: -
Boot sector info:
Operating System:
Boot files/dirs:
=========================== Drive/Partition Info: =============================
Drive: sda ___________________ __________________________________________________ ___
Disk /dev/sda: 30.0 GB, 30005821440 bytes
255 heads, 63 sectors/track, 3648 cylinders, total 58605120 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x2abe2abe
Partition Boot Start End Size Id System
/dev/sda1 63 29,302,559 29,302,497 83 Linux
/dev/sda2 * 29,302,560 58,605,119 29,302,560 f W95 Ext d (LBA)
/dev/sda5 29,302,623 30,844,799 1,542,177 82 Linux swap / Solaris
/dev/sda6 30,844,863 42,459,794 11,614,932 83 Linux
/dev/sda7 42,459,858 58,605,119 16,145,262 83 Linux
blkid -c /dev/null: __________________________________________________ __________
/dev/ramzswap0: TYPE="swap"
/dev/sda1: UUID="aa4e4700-e20d-4f83-b488-c954c4a05b43" SEC_TYPE="ext2" TYPE="ext3"
/dev/sda5: UUID="5ae01f1c-fa97-49ca-9709-2e270bce099c" TYPE="swap"
/dev/sda6: UUID="ab9e619c-fb92-458e-aee5-417116989510" SEC_TYPE="ext2" TYPE="ext3"
/dev/sda7: UUID="f91f8392-1168-464d-8699-419b9932e155" SEC_TYPE="ext2" TYPE="ext3"
/dev/loop0: TYPE="squashfs"
=============================== "mount" output: ===============================
/proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
tmpfs on /lib/modules/2.6.27-7-generic/volatile type tmpfs (rw,mode=0755)
tmpfs on /lib/modules/2.6.27-7-generic/volatile type tmpfs (rw,mode=0755)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
varrun on /var/run type tmpfs (rw,nosuid,mode=0755)
varlock on /var/lock type tmpfs (rw,noexec,nosuid,nodev,mode=1777)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
rootfs on / type rootfs (rw)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
/dev/scd0 on /cdrom type iso9660 (ro,noatime)
/dev/loop0 on /rofs type squashfs (ro,noatime)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
gvfs-fuse-daemon on /home/ubuntu/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=ubuntu)
=========================== sda1/boot/grub/menu.lst: ===========================
# menu.lst - See: grub(8), info grub, update-grub(8)
# grub-install(8), grub-floppy(8),
# grub-md5-crypt, /usr/share/doc/grub
# and /usr/share/doc/grub-doc/.
## default num
# Set the default entry to the entry number NUM. Numbering starts from 0, and
# the entry number 0 is the default if the command is not used.
#
# You can specify 'saved' instead of a number. In this case, the default entry
# is the entry saved with the command 'savedefault'.
# WARNING: If you are using dmraid do not use 'savedefault' or your
# array will desync and will not let you boot your system.
default 0
## timeout sec
# Set a timeout, in SEC seconds, before automatically booting the default entry
# (normally the first entry defined).
timeout 3
## hiddenmenu
# Hides the menu by default (press ESC to see the menu)
hiddenmenu
# Pretty colours
#color cyan/blue white/blue
## password ['--md5'] passwd
# If used in the first section of a menu file, disable all interactive editing
# control (menu entry editor and command-line) and entries protected by the
# command 'lock'
# e.g. password topsecret
# password --md5 $1$gLhU0/$aW78kHK1QfV3P2b2znUoe/
# password topsecret
#
# examples
#
# title Windows 95/98/NT/2000
# root (hd0,0)
# makeactive
# chainloader +1
#
# title Linux
# root (hd0,1)
# kernel /vmlinuz root=/dev/hda2 ro
#
#
# Put static boot stanzas before and/or after AUTOMAGIC KERNEL LIST
### BEGIN AUTOMAGIC KERNELS LIST
## lines between the AUTOMAGIC KERNELS LIST markers will be modified
## by the debian update-grub script except for the default options below
## DO NOT UNCOMMENT THEM, Just edit them to your needs
## ## Start Default Options ##
## default kernel options
## default kernel options for automagic boot options
## If you want special options for specific kernels use kopt_x_y_z
## where x.y.z is kernel version. Minor versions can be omitted.
## e.g. kopt=root=/dev/hda1 ro
## kopt_2_6_8=root=/dev/hdc1 ro
## kopt_2_6_8_2_686=root=/dev/hdc2 ro
# kopt=root=UUID=aa4e4700-e20d-4f83-b488-c954c4a05b43 ro
## default grub root device
## e.g. groot=(hd0,0)
# groot=aa4e4700-e20d-4f83-b488-c954c4a05b43
## should update-grub create alternative automagic boot options
## e.g. alternative=true
## alternative=false
# alternative=true
## should update-grub lock alternative automagic boot options
## e.g. lockalternative=true
## lockalternative=false
# lockalternative=false
## additional options to use with the default boot option, but not with the
## alternatives
## e.g. defoptions=vga=791 resume=/dev/hda5
# defoptions=quiet splash
## should update-grub lock old automagic boot options
## e.g. lockold=false
## lockold=true
# lockold=false
## Xen hypervisor options to use with the default Xen boot option
# xenhopt=
## Xen Linux kernel options to use with the default Xen boot option
# xenkopt=console=tty0
## altoption boot targets option
## multiple altoptions lines are allowed
## e.g. altoptions=(extra menu suffix) extra boot options
## altoptions=(recovery) single
# altoptions=(recovery mode) single
## controls how many kernels should be put into the menu.lst
## only counts the first occurence of a kernel, not the
## alternative kernel options
## e.g. howmany=all
## howmany=7
# howmany=all
## should update-grub create memtest86 boot option
## e.g. memtest86=true
## memtest86=false
# memtest86=true
## should update-grub adjust the value of the default booted system
## can be true or false
# updatedefaultentry=false
## should update-grub add savedefault to the default options
## can be true or false
# savedefault=false
## ## End Default Options ##
title Ubuntu 8.10, kernel 2.6.27-11-generic
uuid aa4e4700-e20d-4f83-b488-c954c4a05b43
kernel /boot/vmlinuz-2.6.27-11-generic root=UUID=aa4e4700-e20d-4f83-b488-c954c4a05b43 ro quiet splash
initrd /boot/initrd.img-2.6.27-11-generic
quiet
title Ubuntu 8.10, kernel 2.6.27-11-generic (recovery mode)
uuid aa4e4700-e20d-4f83-b488-c954c4a05b43
kernel /boot/vmlinuz-2.6.27-11-generic root=UUID=aa4e4700-e20d-4f83-b488-c954c4a05b43 ro single
initrd /boot/initrd.img-2.6.27-11-generic
title Ubuntu 8.10, kernel 2.6.27-7-generic
uuid aa4e4700-e20d-4f83-b488-c954c4a05b43
kernel /boot/vmlinuz-2.6.27-7-generic root=UUID=aa4e4700-e20d-4f83-b488-c954c4a05b43 ro quiet splash
initrd /boot/initrd.img-2.6.27-7-generic
quiet
title Ubuntu 8.10, kernel 2.6.27-7-generic (recovery mode)
uuid aa4e4700-e20d-4f83-b488-c954c4a05b43
kernel /boot/vmlinuz-2.6.27-7-generic root=UUID=aa4e4700-e20d-4f83-b488-c954c4a05b43 ro single
initrd /boot/initrd.img-2.6.27-7-generic
title Ubuntu 8.10, memtest86+
uuid aa4e4700-e20d-4f83-b488-c954c4a05b43
kernel /boot/memtest86+.bin
quiet
### END DEBIAN AUTOMAGIC KERNELS LIST
=============================== sda1/etc/fstab: ===============================
# /etc/fstab: static file system information.
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc defaults 0 0
# /dev/sda1
UUID=aa4e4700-e20d-4f83-b488-c954c4a05b43 / ext3 relatime,errors=remount-ro 0 1
/dev/scd0 /media/cdrom0 udf,iso9660 user,noauto,exec,utf8 0 0
=================== sda1: Location of files loaded by Grub: ===================
11.4GB: boot/grub/menu.lst
11.4GB: boot/grub/stage2
11.4GB: boot/initrd.img-2.6.27-11-generic
11.5GB: boot/initrd.img-2.6.27-7-generic
11.5GB: boot/vmlinuz-2.6.27-11-generic
11.5GB: boot/vmlinuz-2.6.27-7-generic
11.4GB: initrd.img
11.5GB: initrd.img.old
11.5GB: vmlinuz
11.5GB: vmlinuz.old
=========================== sda6/boot/grub/menu.lst: ===========================
# Modified by YaST2. Last modification on Sat Apr 11 02:41:43 EST 2009
default 0
timeout 8
##YaST - generic_mbr
gfxmenu (hd0,5)/boot/message
##YaST - activate
###Don't change this comment - YaST2 identifier: Original name: linux###
title openSUSE 11.1
root (hd0,5)
kernel /boot/vmlinuz-2.6.27.7-9-default root=/dev/disk/by-id/ata-HTS424030M9AT00_MPAA42QBJB1WUB-part6 resume=/dev/disk/by-id/ata-HTS424030M9AT00_MPAA42QBJB1WUB-part5 splash=silent showopts vga=0x317
initrd /boot/initrd-2.6.27.7-9-default
###Don't change this comment - YaST2 identifier: Original name: Ubuntu 8.10, kernel 2.6.27-11-generic (/dev/sda1)###
title Ubuntu 8.10, kernel 2.6.27-11-generic (/dev/sda1)
root (hd0,0)
configfile /boot/grub/menu.lst
###Don't change this comment - YaST2 identifier: Original name: failsafe###
title Failsafe -- openSUSE 11.1
root (hd0,5)
kernel /boot/vmlinuz-2.6.27.7-9-default root=/dev/disk/by-id/ata-HTS424030M9AT00_MPAA42QBJB1WUB-part6 showopts ide=nodma apm=off noresume nosmp maxcpus=0 edd=off powersaved=off nohz=off highres=off processor.max_cstate=1 x11failsafe vga=0x317
initrd /boot/initrd-2.6.27.7-9-default
=============================== sda6/etc/fstab: ===============================
/dev/disk/by-id/ata-HTS424030M9AT00_MPAA42QBJB1WUB-part5 swap swap defaults 0 0
/dev/disk/by-id/ata-HTS424030M9AT00_MPAA42QBJB1WUB-part6 / ext3 acl,user_xattr 1 1
/dev/disk/by-id/ata-HTS424030M9AT00_MPAA42QBJB1WUB-part7 /home ext3 acl,user_xattr 1 2
proc /proc proc defaults 0 0
sysfs /sys sysfs noauto 0 0
debugfs /sys/kernel/debug debugfs noauto 0 0
devpts /dev/pts devpts mode=0620,gid=5 0 0
=================== sda6: Location of files loaded by Grub: ===================
17.4GB: boot/grub/menu.lst
17.4GB: boot/grub/stage2
17.4GB: boot/initrd
17.4GB: boot/initrd-2.6.27.7-9-default
17.4GB: boot/vmlinuz
17.4GB: boot/vmlinuz-2.6.27.7-9-default
=========================== Unknown MBRs/Boot Sectors/etc =======================
Unknown MBR on /dev/sda
00000000 31 c0 8e d0 bc 00 7c 8e c0 8e d8 bf 1e 06 be 1e |1.....|.........|
00000010 7c 50 57 b9 e2 01 f3 a4 b9 00 02 f3 ab cb 80 fa ||PW.............|
00000020 8f 7e 02 b2 80 52 52 bb 94 07 8d af 2a 00 8a 46 |.~...RR.....*..F|
00000030 04 66 8b 7e 08 66 03 3e b3 06 84 c0 74 0b 80 7e |.f.~.f.>....t..~|
00000040 00 80 75 05 66 89 3e 84 0b 83 c5 10 83 c3 09 80 |..u.f.>.........|
00000050 fb b8 75 da b8 e1 00 c1 e0 02 89 c6 66 8b ac 00 |..u.........f...|
00000060 08 66 85 ed 75 19 b8 c5 06 be bb 06 e8 a5 00 89 |.f..u...........|
00000070 c6 e8 9a 00 5a 31 c0 cd 13 cd 18 fb f4 eb fc 66 |....Z1.........f|
00000080 89 2e b3 06 be ab 06 b4 42 5a 52 cd 13 b8 d9 06 |........BZR.....|
00000090 72 d7 a0 00 7c 84 c0 74 03 a1 fe 7d 3d 55 aa b8 |r...|..t...}=U..|
000000a0 e9 06 75 c5 66 89 ee 5a e9 55 75 10 00 01 00 00 |..u.f..Z.Uu.....|
000000b0 7c 00 00 00 00 00 00 00 00 00 00 45 72 72 6f 72 ||..........Error|
000000c0 20 00 0d 0a 00 4e 6f 20 61 63 74 69 76 65 20 70 | ....No active p|
000000d0 61 72 74 69 74 69 6f 6e 00 44 69 73 6b 20 72 65 |artition.Disk re|
000000e0 61 64 20 65 72 72 6f 72 00 4e 6f 20 6f 70 65 72 |ad error.No oper|
000000f0 61 74 69 6e 67 20 73 79 73 74 65 6d 00 49 6e 76 |ating system.Inv|
00000100 61 6c 69 64 20 43 48 53 20 72 65 61 64 00 e8 03 |alid CHS read...|
00000110 00 be c2 06 60 ac b4 0e bb 01 00 cd 10 ac 84 c0 |....`...........|
00000120 75 f4 61 c3 00 00 00 00 00 00 00 00 00 00 00 00 |u.a.............|
00000130 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000140 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000150 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000160 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000170 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000180 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000190 1c 80 b6 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000001a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000001b0 00 00 00 00 00 00 00 00 be 2a be 2a 00 00 00 01 |.........*.*....|
000001c0 01 00 83 fe ff ff 3f 00 00 00 e1 1e bf 01 80 fe |......?.........|
000001d0 ff ff 0f fe ff ff 20 1f bf 01 20 1f bf 01 00 00 |...... ... .....|
000001e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.|
00000200