extlinux zfs problem

[Syn-3] root@darkstar.example.net ~/syslinux-6.04-pre1# sfdisk --dump /dev/hda
label: dos
label-id: 0x3658e4b9
device: /dev/hda
unit: sectors

/dev/hda1 : start=        2048, size=      262144, type=fd, bootable
/dev/hda2 : start=      264192, size=  4294701056, type=fd
[Syn-3] root@darkstar.example.net ~/syslinux-6.04-pre1# mount
devtmpfs on /dev type devtmpfs (rw,relatime,size=2066292k,nr_inodes=212937,mode=755)
devpts on /dev/pts type devpts (rw,relatime,mode=600)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,relatime)
/dev/mapper/syn3-root on / type xfs (rw,noatime,attr2,inode64,noquota)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
/dev/mapper/syn3-home on /home type xfs (rw,noatime,inode32)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,noexec)
/dev/md0 on /boot type xfs (rw)
[Syn-3] root@darkstar.example.net ~/syslinux-6.04-pre1# dd if=mbr/
Makefile      adjust.h      altmbr.S      checksize.pl  gptmbr.S      i386/         isohdpfx.S    isohdppx.S    mbr.S         mbr.ld        oldmbr.asm    x86_64/       
[Syn-3] root@darkstar.example.net ~/syslinux-6.04-pre1# dd if=mbr/^C
[Syn-3] root@darkstar.example.net ~/syslinux-6.04-pre1# find |grep mbr.bin
./efi32/mbr/gptmbr.bin
./efi32/mbr/mbr.bin
./efi32/mbr/altmbr.bin
./efi64/mbr/gptmbr.bin
./efi64/mbr/mbr.bin
./efi64/mbr/altmbr.bin
./bios/mbr/gptmbr.bin
./bios/mbr/mbr.bin
./bios/mbr/altmbr.bin
[Syn-3] root@darkstar.example.net ~/syslinux-6.04-pre1# dd if=bios/mbr/mbr.bin of=/dev/hda
0+1 records in
0+1 records out
[Syn-3] root@darkstar.example.net ~/syslinux-6.04-pre1# bios/extlinux/extlinux -i /boot/
/boot/ is device /dev/md0
[Syn-3] root@darkstar.example.net ~/syslinux-6.04-pre1# sync 
[Syn-3] root@darkstar.example.net ~/syslinux-6.04-pre1# reboot