Error 12: Invalid device requested
Press any key to continue...
If you got that error when trying to follow the same sort of config Win 7 is in your menu.lst for OS X, I don't think that will work...

OS X would probably use a different configuration, if it works with Grub at all. Let me do a little Googling, and see if I come up with anything in regards to getting OS X to boot directly from Grub...
-Coolname007
Addendum:
Ok, I found something...

The advice that I found says this config may work:
Code:
title Mac OS X
rootnoverify (hd0,4)
makeactive
chainloader +1
Test it out, and see if it does.
-Coolname007
EDIT: If that doesn't work, then try the following instructions:
1) Copy the folder "i386" from the OSx cd (which is located at /usr/standalone/i386)and put it in /boot/grub/ The i386 folder is hidden normally so ensure you can see all hidden files in whatever operating system you are currently in. What I did is copied the files over in windows to a flash drive and then copied them from the flash drive to my home space and then used the following command in the terminal: cp -r /home/i386 /boot/grub/i386
2) Go To Applications > System > YaST
3) Go To "System" and select "Boot Loader"
4) Click "Add"
5) Select "Other System (Chainloader)"
6) Type in OSx86 for your Section Name and for Device select browse.
7) Browse to where you saved your i386 folder and select the chain0 file. This means you should have /boot/grub/i386/chain0 in the field where it says device
8) Click OK and you're done.
NOTE: If you try editing the menu.list file straight, it will not show OSx as a choice. You must initially use Yast in order to get the option to show in GRUB then if you desire you can edit it manually. .