samba - Jan 2014 - mixed setup with Windows and Samba 4 DCs replicating eachother, anot supported setup ?????

Hai, 

Through sernet I got the following message, and i want to know if this is
correct.

QUOTE Bj?rn: 
you have a mixed setup with Windows and Samba 4 DCs replicating eachother? 
This would not be a supported setup with Samba 4 currently and that might have
caused the issues you see right now.
QUOTE 

My Answhere, is Yes, i have windows dns+dhcp and 2 x samba4 DC's

Is this true for, non sernet samba, or is this only sernet samba which is not
supporting this.
Because if this is the case then why is there samba4 and is there the option to
join windows domains.


Best regards, 

Louis