Veja o guia de migração do ADMT 3.1:
When you restructure Windows Server
2008 domains in a Windows Server 2008
forest, you can consolidate your
domain structure and reduce
administrative complexity and
overhead. Unlike the process for
restructuring Windows Server 2008
domains between forests, when you
restructure domains in a forest, the
migrated accounts no longer exist in
the source domain. Therefore, rollback
of the migration can only occur when
you carry out the migration process
again in reverse order from the
previous target domain to the previous
source domain.
Important : All target domains must be
operating at either the Windows 2000
native functional level, the Windows
Server 2003 functional level, or the
Windows Server 2008 functional level.
The following table lists the
differences between an interforest
domain restructure and an intraforest
domain restructure.
Poderia ser que seus domínios filhos não estejam no modo nativo?