Comment 6 for bug 73141

(hd1) is the second hard disk in the sytem, which you won't have assuming you only have one raid set and no other disks.

I seem to remember having to change the default from (hd0,0) myself when I first installed grub, but it was so long ago I forget now. Looking at the code though, I think that is the case. It looks like it will need modified to not bail out and default to (hd0,0). Defaulting to hd0 is fine, but it should try to extract the partition number if it can.