Hi, OK Now the problem is solved, i see a grub-install parameter useful :)

--grub-shell=FILE, with this override the use of the problematic /sbin/grub.

1) No chroot is needed.
2) Now the correct grub is installed at MBR/BOOT not the grub-gfx ;)

Patch is attached

--
Gerardo Exequiel Pozzi ( djgera )
http://www.djgera.com.ar
KeyID: 0x1B8C330D
Key fingerprint = 0CAA D5D4 CD85 4434 A219  76ED 39AB 221B 1B8C 330D

--- setup.orig  2009-01-31 18:12:15.000000000 -0200
+++ setup       2009-01-31 18:12:51.000000000 -0200
@@ -1081,7 +1081,7 @@
        DIALOG --msgbox "GRUB root and setup devices could not be auto-located.  You will need to manually run the GRUB shell to install a bootloader." 0 0
        return 1
    fi
-    $DESTDIR/sbin/grub-install --recheck --root-directory=$DESTDIR $ROOTDEV >/tmp/grub.log 2>&1
+    $DESTDIR/sbin/grub-install --recheck --grub-shell=$DESTDIR/sbin/grub --root-directory=$DESTDIR $ROOTDEV >/tmp/grub.log 2>&1
    cat /tmp/grub.log >$LOG
    # unfreeze xfs filesystems
    if [ -x /usr/sbin/xfs_freeze ]; then