SLP AIR secondary duplication operation different retention to source.

Hi - I have two Nbu domains both running 7.6 with AIR SLP's between each. The master on each domain is the DR master for the alternate domain

Site 1 has an SLP setup for the backup and replication operations and site 2 has an SLP the import and duplication.

I have a backup copy on disk for 6 months at the primary site which is replicated to disk at the secondary site and also held for 6 months. I then wish to duplicate to tape after 6 months at the secondary site when the disk image is due to expire, with the tape copy to be held for 1 year (from the backup start time).

My understanding is that the SLP at the target domain needs to have a fixed and target retention for its operations.

I want to deploy deferred duplication using the Postpone creation of this copy until the source is about to expire check box, for the duplication operation but when I save the policy I get an error 1507, Invalid deferred operation flag -

http://www.symantec.com/business/support/index?page=content&id=HOWTO105324

I think this is due to the source data i.e. the import operation, having to have a fixed retention.

If the SLP target’s import operation is changed to a fixed retention, we would then have to set the duplication operation to a target retention. The retention of the duplication operation therefore would be remote/the source retention and be only 6 months.

This does not give me the retention on tape using deferred duplication that I require as it is matching the source retention.

How do I set up the SLP for the target domain so that the secondary operation has a deferred and different retention to the source operation?