gub-install error

[Rodrigo Fresneda]

Hi, I got this error when trying to 

#> grub-install /dev/md_d0

/usr/sbin/grub-probe: error: unknown filesystem.
Auto-detection of a filesystem of /dev/md_d0p1 failed.

The output of "/usr/sbin/grub-probe --device-map=/boot/grub/device.map
--target=fs -v /boot/grub" is

/usr/sbin/grub-probe: info: the size of hd0 is 312581808.
/usr/sbin/grub-probe: info: the size of hd0 is 312581808.
/usr/sbin/grub-probe: info: the size of hd0 is 312581808.
/usr/sbin/grub-probe: info: the size of hd1 is 312581808.
/usr/sbin/grub-probe: info: the size of hd1 is 312581808.
/usr/sbin/grub-probe: info: the size of hd1 is 312581808.
/usr/sbin/grub-probe: info: the size of hd0 is 312581808.
/usr/sbin/grub-probe: info: the size of hd0 is 312581808.
/usr/sbin/grub-probe: info: the size of hd0 is 312581808.
/usr/sbin/grub-probe: info: the size of hd1 is 312581808.
/usr/sbin/grub-probe: info: the size of hd1 is 312581808.
/usr/sbin/grub-probe: info: the size of hd1 is 312581808.
/usr/sbin/grub-probe: info: changing current directory to /dev.
/usr/sbin/grub-probe: info: changing current directory to snd.
/usr/sbin/grub-probe: info: changing current directory to by-path.
/usr/sbin/grub-probe: info: changing current directory to cpu.
/usr/sbin/grub-probe: info: changing current directory to shm.
/usr/sbin/grub-probe: info: opening md/d0.
/usr/sbin/grub-probe: error: unknown filesystem.


And the detail of my raid array are:

/dev/md_d0:
        Version : 1.2
  Creation Time : Mon Dec 20 15:04:52 2010
     Raid Level : raid1
     Array Size : 156287225 (149.05 GiB 160.04 GB)
  Used Dev Size : 156287225 (149.05 GiB 160.04 GB)
   Raid Devices : 2
  Total Devices : 2
    Persistence : Superblock is persistent

    Update Time : Wed Mar 30 15:09:55 2011
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

           Name : fresnet:d0  (local to host fresnet)
           UUID : bec84d33:d38d6f54:0fa9b030:856dce73
         Events : 4144

    Number   Major   Minor   RaidDevice State
       0       8       17        0      active sync   /dev/sdb1
       2       8        1        1      active sync   /dev/sda1


regards,
rodrigo.