How to change hd number in /boot/grub/grub.cfg

[Norval Watson]

 Hi,
I have a system with several bootable debian partitions on first SATA hard 
drive 
and data on second.
i am running grub-pc v 1.98 on two partitions but legacy grub on a third.

In grub2 /boot/grub/grub.cfg lists all my bootable partitions as hd1 when they 
should be hd0
my /boot/grub/device.map looks like

(hd0)    /dev/disk/by-id/ata-ST3320620AS_5QF4WWFK
(hd1)    /dev/disk/by-id/ata-ST3320620AS_9QF49FLL
(hd2)    /dev/disk/by-id/usb-Verbatim_Store_n_Go_Mini_fee76a83794000-0:0

I have tried to fix this from a usb rescue image, trying

dpkg-reconfigure grub-pc
grub-install /dev/sda
update-grub
upgrade-from-grub-legacy

but /boot/grub/grub.cfg still contains entries like 

set root='(hd1,msdos2)'
search --no-floppy --fs-uuid --set d61ef63d-73ad-418d-93e1-5a7f6c1ce29b

I don't have any custom entries in /etc/grub.d/... or in /etc/default/grub
I had to rewrite the partition table with fdisk at some stage coz all the 
bootable flags disappeared.
Now I can boot if I edit the boot stanzas from the grub screen and change hd1 
to 
hd0.
Any help appreciated!
Thanks
Norv