So please, S.W., if you can, do the tests again so that there would be meaningful data about where Ubuntu currently is vs. eg. Mandriva. Or someone else. I agree that it's unfortunate that Ubuntu's installer doesn't detect all the other distributions, though if you overwrite your previous grub it's quite easy to do chroot /media/otherpartition ; grub-install hd0 to get back using the previous configuration. It's also easy to then add ubuntu entry to that other partition's /boot/grub/menu.lst
So please, S.W., if you can, do the tests again so that there would be meaningful data about where Ubuntu currently is vs. eg. Mandriva. Or someone else. I agree that it's unfortunate that Ubuntu's installer doesn't detect all the other distributions, though if you overwrite your previous grub it's quite easy to do chroot /media/ otherpartition ; grub-install hd0 to get back using the previous configuration. It's also easy to then add ubuntu entry to that other partition's /boot/grub/menu.lst