Slackware :: How To Chainboot Slackware From Grub2

I've made a mini installation of slackware64-13.1 onto my friend's computer. He already has Ubuntu and Windows partitions that are being handled by GRUB2. I thought the best thing to do would be to have lilo installed to the partition root (on /dev/sda3) and let grub2 chainboot. I've been reading about adding custom entries to the grub menu and things look like they're working but then I reboot and there's no Slackware option.

Currently I've got this file in /etc/grub.d/41_slack. It is executable.

Code:

#!/bin/sh -e
echo "Adding Slackware"
cat << EOF
menuentry "Slackware" {
set root=(hd0,3)
chainloader (hd0,3)+1
}
EOF

When I run "sudo update-grub" this is the output

Code:

lewi@benny:~$ sudo update-grub
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-2.6.32-22-generic
Found initrd image: /boot/initrd.img-2.6.32-22-generic

[code]...

So it has found the slackware partition (not because of my menu entry though?) but when I reboot there's no menu entry there.