Try the following in a terminal to update your bootloader:
sudo update-grub
You'll see something like this:
Found linux image: /boot/vmlinuz-3.0.0-14-generic
Found initrd image: /boot/initrd.img-3.0.0-14-generic
Found linux image: /boot/vmlinuz-3.0.0-12-generic
Found initrd image: /boot/initrd.img-3.0.0-12-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Windows 7 (loader) on /dev/sda1
Found Windows 7 (loader) on /dev/sda2
Found Windows Recovery Environment (loader) on /dev/sda3
Look for /dev/sda8
in there, if its not there then you have another problem.
If /dev/sda8
shows up, reboot your computer and look at the bootloader (purple screen) before Ubuntu starts to boot. At that point, just look around - I suspect that you'll find 11.10 down at the bottom of that menu.