Cloning a Solaris 11 Express NGZ with delegate datasets fails and marks original NGZ incomplete!

Hello,
I had the following Solaris 11 Express NGZ which I intended to clone as sort of backup.
Instead of a backup I think I've lost everything!

# zonecfg -z s11-z4 export | zonecfg -z s11-z4-bak -f -
# zonecfg -z s11-z4-bak "set zonepath=/zones/s11-z4-bak"
# zonecfg -z s11-z4-bak info
zonename: s11-z4-bak
zonepath: /zones/s11-z4-bak
brand: ipkg
autoboot: false
bootargs:
pool:
limitpriv:
scheduling-class:
ip-type: exclusive
hostid:
fs-allowed:
net:
    address not specified
    allowed-address not specified
    physical: n3                                               (I've kept this from s11-z4)
    defrouter not specified
dataset:
    name: zones/users/z4                               (I've kept this from s11-z4)