[quote]### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
    linux    /memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
    linux    /memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Ubuntu jaunty (development branch), kernel 2.6.28-9-generic (on /dev/sda1)" {
    set root=(hd0,1)
    search --no-floppy --fs-uuid --set b91170ae-6234-41e9-b8e9-0e2c82ae4e33
    linux /boot/vmlinuz-2.6.28-9-generic root=UUID=13accb1e-1bfb-4b98-9b1f-f413eec72138 ro quiet splash
    initrd /boot/initrd.img-2.6.28-9-generic
}
menuentry "Ubuntu jaunty (development branch), kernel 2.6.28-9-generic (recovery mode) (on /dev/sda1)" {
    set root=(hd0,1)
    search --no-floppy --fs-uuid --set b91170ae-6234-41e9-b8e9-0e2c82ae4e33
    linux /boot/vmlinuz-2.6.28-9-generic root=UUID=13accb1e-1bfb-4b98-9b1f-f413eec72138 ro single
    initrd /boot/initrd.img-2.6.28-9-generic
}
menuentry "Ubuntu jaunty (development branch), memtest86+ (on /dev/sda1)" {
    set root=(hd0,1)
    search --no-floppy --fs-uuid --set b91170ae-6234-41e9-b8e9-0e2c82ae4e33
    linux /boot/memtest86+.bin
}

### BEGIN /etc/grub.d/30_otheros ###

# This entry automatically added by the Debian installer for an existing
# linux installation on /dev/sda1.
menuentry "Ubuntu jaunty (development branch), kernel 2.6.28-9-generic (on /dev/sda1)" {
    set root=(hd0,1)
    search --no-floppy --fs-uuid --set b91170ae-6234-41e9-b8e9-0e2c82ae4e33
    linux /boot/vmlinuz-2.6.28-9-generic root=UUID=b91170ae-6234-41e9-b8e9-0e2c82ae4e33 ro quiet splash
    initrd /boot/initrd.img-2.6.28-9-generic
}


# This entry automatically added by the Debian installer for an existing
# linux installation on /dev/sda1.
menuentry "Ubuntu jaunty (development branch), kernel 2.6.28-9-generic (recovery mode) (on /dev/sda1)" {
    set root=(hd0,1)
    search --no-floppy --fs-uuid --set b91170ae-6234-41e9-b8e9-0e2c82ae4e33
    linux /boot/vmlinuz-2.6.28-9-generic root=UUID=b91170ae-6234-41e9-b8e9-0e2c82ae4e33 ro single
    initrd /boot/initrd.img-2.6.28-9-generic
}


# This entry automatically added by the Debian installer for an existing
# linux installation on /dev/sda1.
menuentry "Ubuntu jaunty (development branch), memtest86+ (on /dev/sda1)" {
    set root=(hd0,1)
    search --no-floppy --fs-uuid --set b91170ae-6234-41e9-b8e9-0e2c82ae4e33
    linux /boot/memtest86+.bin 
}[/quote]

The first jaunty recorded by :
[quote]/etc/grub.d/30_os-prober [/quote]