Cannot receive incremental stream: dataset is busy

I am using an Oracle 7320 ZFS appliance and seeing an issue when trying to perform an incremental restore of an iSCSI LUN using NetBackup.  

Full restores work just fine but I receive the following message when trying to perform an incremental restore:

 Cannot receive incremental stream: dataset is busy

I am using the following NDMP environment variables:

SET TYPE=zfs

SET ZFS_FORCE=y

I have tried toggling the rollback setting to "Always rollback datasets", "Only rollback if specified by DMA" and "Never rollback datasets" (tried to do a manual rollback prior to incremental restore).  All three settings seem to result in the same error message.