v0.9 - live migration and vdi locking is conflicted

I'm testing sheepdog 0.9 on two hosts.

I tried to do kvm live migration:
$ virsh migrate --live test-vm qemu+ssh://test-host2/system

but I get the following error:
error: internal error: process exited while connecting to monitor: qemu-system-x86_64: -drive file=sheepdog:test-vm-disk,if=none,id=drive-virtio-disk0,format=qcow2,cache=none: cannot get vdi info, VDI is already locked, test-vm-disk 0
qemu-system-x86_64: -drive file=sheepdog:test-vm-disk,if=none,id=drive-virtio-disk0,format=qcow2,cache=none: could not open disk image sheepdog:test-vm-disk: Could not open 'sheepdog:test-vm-disk': Input/output error

the VDI is locked by dog:
$ dog vdi lock list
VDI | owner node
test-vm-disk | IPv4 ip:test-host1 port:7000

if I remove the VDI lock the live migration works correctly:
$ dog vdi lock unlock test-vm-disk

but after the live migration I can't relock the VDI.

VM disk definition:
    <disk type='network' device='disk'>
      <driver name='qemu' type='qcow2' cache='none'/>
      <source protocol='sheepdog' name='test-vm-disk'/>
      <target dev='vda' bus='virtio'/>
    </disk>

os: Ubuntu 14.04.1 LTS
qemu: QEMU emulator version 2.0.0 (Debian 2.0.0+dfsg-2ubuntu1.7)
sheepdog: Sheepdog daemon version 0.9.0