samba - Nov 2013 - can't join MS Server 2012 domain as DC with 4.1.2

Hello,

I'm trying to join an Arch Linux server as a DC to an existing domain
with functional level Windows Server 2012 (5), but I'm getting the
following error: DsAddEntry failed with status (5, 'WERR_ACCESS_DENIED')
info (8567, 'WERR_DS_INCOMPATIBLE_VERSION'). Exchange 2013 is also
installed on this domain by the way.

Part of the output of samba-tool domain level -h is:

--forest-level=FOREST_LEVEL
                        The forest function level (2003 | 2008 | 2008_R2)
--domain-level=DOMAIN_LEVEL
                        The domain function level (2003 | 2008 | 2008_R2)

Does this mean functional level 2012 is not yet supported by samba 4.1.2?

Tiemen