Comment 4 for bug 1065801

And just handing boot off to an older grub2 OS results in ridiculously long and sometimes totally incorrect menu items like:

menuentry "Ubuntu quantal (development branch), kernel 3.5.0-15-generic (on /dev/sda15)' --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-/boot/vmlinuz-3.5.0-15-generic--562a6d98-7630-445d-b3eb-186990955537 (on /dev/sda16)" --class gnu-linux --class gnu --class os {
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos16)'
 search --no-floppy --fs-uuid --set=root f3221ba1-36a8-42d5-9205-8d873e8ecb4f
 linux /boot/vmlinuz-3.5.0-15-generic root=UUID=562a6d98-7630-445d-b3eb-186990955537 ro quiet splash
 initrd /boot/initrd.img-3.5.0-15-generic
}
menuentry "Ubuntu quantal (development branch), kernel 3.5.0-15-generic (recovery mode) (on /dev/sda15)' --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-/boot/vmlinuz-3.5.0-15-generic-root=UUID=562a6d98-7630-445d-b3eb-186990955537 ro single-562a6d98-7630-445d-b3eb-186990955537 (on /dev/sda16)" --class gnu-linux --class gnu --class os {
 insmod part_msdos
 insmod ext2
 set root='(hd0,msdos16)'
 search --no-floppy --fs-uuid --set=root f3221ba1-36a8-42d5-9205-8d873e8ecb4f
 linux /boot/vmlinuz-3.5.0-15-generic root=UUID=562a6d98-7630-445d-b3eb-186990955537 ro single
 initrd /boot/initrd.img-3.5.0-15-generic

You'll notice in one place it mentions sda15 but in another it mentions sda16.

So booting the correct OS is now like rolling the dice.