Dale, you didn't describe the symptoms you're seeing, but maybe just seeing how I did it will help:
menuentry "memtest86" {
search -l gentoo64unstable -s root
linux ($root)/boot/memtest86/memtest
boot
}
Note that gentoo64unstable is the label I gave my root partition.
I do that in case I hot-plug a disk that changes the /dev/name of
the partition. That's the reason I switched to grub2 originally.
(You can search instead for the UUID if you prefer to use that.)
