I have lost count of how many times I have re-installed Ubuntu 12 (well, about 4). The problem with my machine is that I have 2 hard disks that are SATA. openSUSE, with grub-legacy, was able to create a boot screen for itself, Windows 7 and Ubuntu 12. The Ubuntu 12choice did not work and gave me the error 15 (and then 13 at some point, and then 17 when I started randomly changing things at the grub command line).
The odd thing is, when I changed the boot order in the BIOS, Ubuntu loaded. So, I decided this morning to install the boot loader in the first hard disk and not the one on which Ubuntu 12 was located. This created a functioning boot menu! I believe that the openSUSE boot menu is still on the second disk, but it is not being reached once the first boot order is found.
Now, I want to make it look pretty.