SNC & CUA

We are having CUA set-up with 4.7 (Unicode) as master and CRM as child system. We have also enabled SNC on 4.7 (Unicode) system where as CRM system is non-Unicode and SNC not enabled. When i try to create user and assign profiles in Master, user gets created in child system but profiles are not assigned. In fact, IDOC posting gives error in child system.

I want to know whether SNC is required on both systems? Error message says 'target system requires SNC'.

Any ideas?

Thanks,