setup (hd0) fails

[Benedict Bridgewater]

Some background:

I've got a Windows 95/Linux setup on dual SCSI drives.

Using GRUB 0.5.95 as comes with Mandrake 7.1

/dev/sda1 2GB FAT16 Windows95 C:
/dev/sda5 1GB ext2fs

/dev/sdb1 4GB FAT32 D:
/dev/sdb5 3GB ext2fs mounted as / (contains /boot, and /boot/grub)

Initially I had LILO installed in the /dev/sda MBR, and could boot into Windows 
and and old verison of Linux in /dev/sda5 as well as the new Mandrake 7.1 whose 
root directory is in /dev/sdb5.

Here's the problem:

Running from Mandrake with /dev/sdb5 mounted as /, I tried to install GRUB to 
replace LILO in the /dev/sda MBR. To do this I ran grub and gave the commands:

> root (hd1,4)
> setup (hd0)

I got an unexpected error from the setup command (reported by embed, if I 
remember correctly), saying that (hdo) was invalid, so I instead tried (hd0,0) 
which it accepted, but turns out to have been a bad idea since it has 
overwritten my Windows boot sector (hopefully "sys c:" from a Windows rescue 
floppy will restore this tonite!).

Am I right in thinking that setup (hd0) *SHOULD* have worked?

If I'm right in thinking this is a bug, then is there any known work-around? 
Would the latest GRUB 0.5.96 fix this?

Ben