Grub boot menu -- very strange occurrence

One extremely weird thing happened while reorganizing my /boot/grub/menu.lst (now in Ubuntu / partition on /dev/sdb2).
Here is the main part of this file in the form that works fine in that all OSes boot perfectly:

title Ubuntu Jaunty 2.6.28-13-generic
root (hd1,1)
kernel /boot/ubuntu/vmlinuz-2.6.28-13-generic root=/dev/sdb2 ## noatime clocksource=hpet
initrd /boot/ubuntu/initrd.img-2.6.28-13-generic

title ****************Other OSes***********************
root

title Linux Mint 7 Gloria, kernel 2.6.28-11-generic
root (hd1,1)
kernel /boot/mint/vmlinuz-2.6.28-11-generic root=/dev/sdb7 ro quiet splash
initrd /boot/mint/initrd.img-2.6.28-11-generic
quiet

title OpenSUSE 11.2 2.6.30.2-1-default
root (hd1,1)
kernel /boot/opensuse/vmlinuz-2.6.30.2-1-default root=/dev/sda1 splash=silent quiet showopts
initrd /boot/opensuse/initrd-2.6.30.2-1-default


title Haiku (500 MB raw image) r31765 11-07-2009
rootnoverify (hd1,4)
chainloader +1

However, the stanza

title ****************Other OSes***********************
root

was added only because, without it, trying to boot Ubuntu gives an error 15 (File not Found).
I really have no idea why this happens. It seems to defy all logic but I've done it so many times that I know it's not an aberration. I think I'll post to perhaps the Ubuntu forum on this as it is so strange.