Question with raising the domain level function.

Archived from groups: microsoft.public.win2000.setup_upgrade (More info?)

Currenly I am in the process of upgrade our organization from NT to W2K3. I
have created a root domain and upgraded the NT domains as a child. I still
have more domains to upgrade and add as a child. I also have other NT
domains that are going to be migrated and domain removed. The whole
enterprise is running in mixed mode at this point.
I had talked with a Microsoft tech on a support call for a DNS issue and he
mentioned that I should stay in mixed mode untill all the NT domains have
been upgraded. I cannot do a migration until I am in at least "native mode"
Can someone confirm this for me? I just need to know if I up my function
level will it cause me any problems with upgrading my other NT domains? The
more I think of this, I cannot see why it should be a problem.

Thanks,

MikeB