Upgrade from 4.6 to 6.5 - UNK problem on client?

Hi

We know that we have to upgrade all of the servers to 4.6.7a to ensure that we can replicate the NAB and maintain co-existance.

What do we need to do about remote users on 4.6.3 who also replicate the NAB. We will not upgrade these users to 6.5 for 3 - 6 months but we want to ensure that they do not have replication problems.

I really want to avoid upgrading them to 4.6.7a first and then upgrading them again to 6.5

Does the UNK problem affect the Notes Client at all ?

Thanks

Martin