What code level are you running?  Cloning a destination NAS server for DR testing was added in v3.0 code.  See: [URL]
I am the only one that finds it absolutely ridiculous that NAS replication can't be tested at all? Not only is a fail-over test not possible, but we can't even clone out the replicas to check them?! This makes NAS replication worthless if I can't verify that it's reliable.
Lack of NAS Failover Test