Problem with device mapping

[Kevin .]

There seems to be an incoherence with the device mapping in my grub. I have two
hard-drives, one is new and still completely empty (my sda in Linux), and the other
is my old one (sdb). In '/boot/grub/device.map' file they are shown to be mapped
as hd0 and hd1, respectively. So I should specify hd1 when I wanted to boot to my OS'es,
however that doesnt work, I have to specify hd0 instead. In the grub command line
I get something like this:

   set root=(hd1,2)
   linux /boot/vmlinuz...
   error: partition doesn't exists

Below are the outputs of fdisk and device.map. I created a partition in sda just to test
if grub was ignoring it for being an empty HD. However nothing changed.

   $ sudo fdisk -l /dev/sda
 
   Disk /dev/sda: 500.1 GB, 500107862016 bytes
   255 heads, 63 sectors/track, 60801 cylinders
   Units = cylinders of 16065 * 512 = 8225280 bytes
   Sector size (logical/physical): 512 bytes / 512 bytes
   I/O size (minimum/optimal): 512 bytes / 512 bytes
   Disk identifier: 0xc7d79935
 
      Device Boot      Start         End      Blocks   Id  System
   /dev/sda1               1        1000     8032468+  83  Linux
 
   $ fdisk -l /dev/sdb
 
   Disk /dev/sdb: 320.1 GB, 320072933376 bytes
   255 heads, 63 sectors/track, 38913 cylinders
   Units = cylinders of 16065 * 512 = 8225280 bytes
   Sector size (logical/physical): 512 bytes / 512 bytes
   I/O size (minimum/optimal): 512 bytes / 512 bytes
   Disk identifier: 0x000470e5
 
      Device Boot      Start         End      Blocks   Id  System
   /dev/sdb1   *           1        1959    15728640   a6  OpenBSD
   Partition 1 does not end on cylinder boundary.
   /dev/sdb2            1959        4390    19530752   83  Linux
   Partition 2 does not end on cylinder boundary.
   /dev/sdb3   *        4390        4403      102400    7  HPFS/NTFS
   Partition 3 does not end on cylinder boundary.
   /dev/sdb4            4403       14834    83783680    7  HPFS/NTFS
   Partition 4 does not end on cylinder boundary.
 
   $ grub-mkdevicemap
   $ cat /boot/grub/device.map
   (hd0)    /dev/sda
   (hd1)    /dev/sdb