I copied my XP install to the drive, planning to simply point grub to (hd1,0) (Hard drive 2, partition 1... For internal, it is (hd0,0) for OSX, (hd0,1) for XP, and (hd0,4) for Ubuntu)) But this did not work. I tried (hd1,0), (hd1,1), (hd2,0), (hd2,1). None worked. But I think the problem is more of Grub not seeing the card than the config file being wrong.
Any help is appreciated!