In order to get a clearer picture of your setup, how about downloading the Boot Info Script (https://sourceforge.net/projects/bootinfoscript/) to your Ubuntu desktop, open a terminal (Applications > Accessories > Terminal) and 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 that file to your next post, highlight the copied text, and click the pound sign # graphic 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.
============================= Boot Info Summary: ==============================
=> Grub0.97 is installed in the MBR of /dev/sda and looks on the same drive
in partition #1 for /boot/grub/stage2 and /boot/grub/menu.lst.
=> No boot loader is installed in the MBR of /dev/sdb
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: -
Boot sector info:
sda5: __________________________________________________ _______________________
File system: swap
Boot sector type: -
Boot sector info:
sdb1: __________________________________________________ _______________________
File system: ntfs
Boot sector type: Windows Vista
Boot sector info: No errors found in the Boot Parameter Block.
Operating System: Windows Vista
Boot files/dirs:
=========================== Drive/Partition Info: =============================
Drive sda: __________________________________________________ ___________________
Disk /dev/sda: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x45c845c7
Partition Boot Start End Size Id System
/dev/sda1 * 63 471,684,464 471,684,402 83 Linux
/dev/sda2 471,684,465 488,392,064 16,707,600 5 Extended
/dev/sda5 471,684,528 488,392,064 16,707,537 82 Linux swap / Solaris
Drive sdb: __________________________________________________ ___________________
Disk /dev/sdb: 1500.3 GB, 1500301910016 bytes
255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x000e3e7a
Partition Boot Start End Size Id System
/dev/sdb1 * 2,048 2,930,274,303 2,930,272,256 7 HPFS/NTFS
/dev/sdb1 ends after the last cylinder of /dev/sdb
blkid -c /dev/null: __________________________________________________ __________
/dev/sda1: UUID="96959348-866e-4f1d-b940-006cb3cb07e1" TYPE="ext3"
/dev/sda5: UUID="a7a3a3b6-9a4b-4eec-a686-7ab3f36952cb" TYPE="swap"
/dev/sdb1: UUID="A6F46886F4685A97" TYPE="ntfs"
=============================== "mount" output: ===============================
/dev/sda1 on / type ext3 (rw,relatime,errors=remount-ro)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
/proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
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)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
lrm on /lib/modules/2.6.27-11-generic/volatile type tmpfs (rw,mode=755)
securityfs on /sys/kernel/security type securityfs (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
gvfs-fuse-daemon on /home/orval/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=orval)
=========================== 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 30
## hiddenmenu
# Hides the menu by default (press ESC to see the menu)
# 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
title Vista
root (hd1,0)
makeactive
chainloader +1
### 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=96959348-866e-4f1d-b940-006cb3cb07e1 ro
## default grub root device
## e.g. groot=(hd0,0)
# groot=96959348-866e-4f1d-b940-006cb3cb07e1
## 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
uuid 96959348-866e-4f1d-b940-006cb3cb07e1
kernel /boot/vmlinuz-2.6.27-11-generic root=UUID=96959348-866e-4f1d-b940-006cb3cb07e1 ro quiet splash
initrd /boot/initrd.img-2.6.27-11-generic
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=96959348-866e-4f1d-b940-006cb3cb07e1 / ext3 relatime,errors=remount-ro 0 1
# /dev/sda5
UUID=a7a3a3b6-9a4b-4eec-a686-7ab3f36952cb none swap sw 0 0
/dev/scd0 /media/cdrom0 udf,iso9660 user,noauto,exec,utf8 0 0
=================== sda1: Location of files loaded by Grub: ===================
152.0GB: boot/grub/menu.lst
151.9GB: boot/grub/stage2
151.9GB: boot/initrd.img-2.6.27-11-generic
151.9GB: boot/initrd.img-2.6.27-7-generic
151.9GB: boot/vmlinuz-2.6.27-11-generic
151.9GB: boot/vmlinuz-2.6.27-7-generic
151.9GB: initrd.img
151.9GB: initrd.img.old
151.9GB: vmlinuz
151.9GB: vmlinuz.old